Is it actually worth retaking A-levels?

Definition of “better” is subjective and you need to look at your subject in particular as well as the university overall. In terms of rankings, go with the QS World rankings which is what universities look at, and in the current climate financial stability is important. Southampton is in the top 80 globally, Chemistry there has world class research and they are financially solid and expanding unlike the vast majority of others. I agree - Southampton every time.

A lot of people seem to be disappointed by the grade boundaries this year but I’m sure it will work out in the end. What were your firm and insurance originally?

I got BBC on results day and missed my firm and insurance offers pretty badly (A*A*A and A*AA respectively) - I'm pretty disappointed but not too surprised given my not so great preparation and near constant stress over the past 2+ years of the war in Ukraine that my family has been severely affected by. I can see where I went badly wrong with my preparation and I feel like I now have the motivation to do better in order to get into a better university compared to what I have in clearing currently (Loughborough and Southampton, both for chemistry), but is it actually realistic to improve from BBC to something like AAA at the minimum in just a year? If anyone has retaken their A-levels successfully, then I'd appreciate any advice you could give on how best to relearn content independently (i.e. through tutors, online courses, etc...) and whether going to a perceived "better" university actually makes that much of a difference.
For context, I may also only need to retake two A-levels if I'm able to get an A in biology after a remark.

No autumnal re-sits? This is false. I re-sat physics, chemistry, maths and further maths at A-level at Hills Road College in the UK, autumn 2021. What are the other 'inaccuracies'?

I got BBC on results day and missed my firm and insurance offers pretty badly (A*A*A and A*AA respectively) - I'm pretty disappointed but not too surprised given my not so great preparation and near constant stress over the past 2+ years of the war in Ukraine that my family has been severely affected by. I can see where I went badly wrong with my preparation and I feel like I now have the motivation to do better in order to get into a better university compared to what I have in clearing currently (Loughborough and Southampton, both for chemistry), but is it actually realistic to improve from BBC to something like AAA at the minimum in just a year? If anyone has retaken their A-levels successfully, then I'd appreciate any advice you could give on how best to relearn content independently (i.e. through tutors, online courses, etc...) and whether going to a perceived "better" university actually makes that much of a difference.
For context, I may also only need to retake two A-levels if I'm able to get an A in biology after a remark.

Either of these unis would be fine - they are both good.

No autumnal re-sits? This is false. I re-sat physics, chemistry, maths and further maths at A-level at Hills Road College in the UK, autumn 2021. What are the other 'inaccuracies'?

Would you say there's a big difference between those two unis, especially Southampton since that's the one I'm thinking of accepting, and something like Bath for chemistry (seeing as that was my insurance choice)? I'm weighing up the risks of retaking so I'm wondering if it's actually worth it in the end.
P.S. any particular preference between Loughborough and Southampton? I've heard that Southampton is perhaps slightly better, specifically for chemistry - is that true? I also know that Loughborough is very sporty but I don't feel like I play any sport at a high enough level to actually benefit from that.

Also false is that higher grades imply better teaching ... only a few unis require lecturers to hold teaching qualifications and one is Brookes!

Is either offering accomodation? Which course appeals more?
The two places are very different - Southampon is a city and Loughborough much smaller.

Both are offering accommodation but I probably like the Southampton course more from looking at the modules. I suppose my main question is more about Southampton vs unis like Bath that I applied for since I'm worried that Southampton may be a step down and it might actually be worth retaking next year (or not, maybe the university you go to isn't that important like others have said in this thread).

The uni you go to isn't important except for a few degrees and Chemistry isn't one of those. My nephew went to Southampton and loved it ... as did the people I know who went to Loughborough. I honestly wouldn't resit in your shoes.

Oh yes, teaching quality is exceedingly, excessively important. I would then go on to say that a bad lecturer is capable of not just driving everyone's grade down, but causing severe motivation issues. I have seen this with my own eyes on the quantum mechanics course this year.
Once again, a better university typically results in better quality teaching. Better quality teaching typically results in higher grades for the average student.

The uni you go to isn't important except for a few degrees and Chemistry isn't one of those. My nephew went to Southampton and loved it ... as did the people I know who went to Loughborough. I honestly wouldn't resit in your shoes.

I did just want to ask how important the university that you go to is to employers abroad since that's something I've considered in the past - I worry that some foreign employers might have just not heard of my university (wherever I end up) and put me at a potential disadvantage.

Southampton is RG if that's important?

This is just not true - look at the teaching quality stats!

Have you heard the saying that statistics are worse than 'damn lies'?
There really is no argument that teaching quality is perhaps the most important thing in university exterior to you.
In all seriousness, let's sit and think.
You are on a course which you like but do not put much effort into. You live in the moment, you are the average student who will graduate with a good 2.1.
1) You have a terrible lecturer. The lecturer reads in a confusing manner, with near-illegible handwriting. You do not understand anything in lectures, which has the effect of necessitating constant attention outside of lectures. When it is time to do a test, you sit staring blankly at the screen and madly scramble through your notes to try and find where he explained it. Desperate, you resort to ChatGPT to pass the quiz. (Quantum mechanics this year. By far the least popular module)
2) You have an excellent lecturer, capable of explaining even the most difficult topic in the most concise and accurate form possible. You understand everything in lectures. When you get assignments, you are able to do them immediately and accurately just based on your notes, which are of exceptional quality and clarity. (Mathematical methods this year. Fourier transforms are commonly considered extremely hard, but due to teaching quality, they were easier to understand than some 'easier' topics from year 1 when the lecturer was unfathomably worse)
There is no argument here. Teaching quality is exceedingly, excessively important. Full stop. The only case in which it would not be important is if your passion for the subject was such that you simply didn't care and did what was necessary. But that is unfortunately not the average student, which I have observed with my own eyes are placed at a massive disadvantage on the exam due to bad teaching quality.
This is why it is preferable to be in a more prestigious university since they usually have better teaching quality

I do agree that teaching quality is hugely important. Along with feedback and assessment quality.
But in my extensive experience over the years, your belief that prestigue automatically leads to better is simply not the case. Nor is there an automatic link between being RG and being top 25. There is a massive overlap in quality out there between RG and non-RG and it really does change on a subject by subject basis. And certainly not for UG experience where lecturers may be employed for their research expertise rather than their ability to teach. Its best not on over simplify like this, or you may miss a gem of a course in your search.

Seriously, the best way to pick a university is to research what sort of institution would suit you best, with the modules you would find interesting, and visit on open days to see if the vibe.
In this case, if that is Southampton, then I would definitley accept the offer. I have relatives at Bath and Loughbough and my daughter is at Southampton. There really isn't a whole lot to choose between them that doesn't come down to personal preference and probably not worth a retake year, unless there is a very specific reason why you would want to go to Bath.