IBDP or A-levels? Any advice would be helpful!

Previously I was set on A-levels but I’ve gotten into a sixth form which offers IBDP and I’m now considering the opportunity much more. My A-levels would be Physics, Maths, Politics and Spanish so I definitely like the idea of having breadth in my subjects. My main concern is that I won’t be able to get into a good uni course or that I can’t keep up with the workload. Firstly, I want to do engineering at the moment but I’ve heard offers for IB students are way harder to meet (the A-level ones are hard enough for good universities) and I don’t know if I want to risk it. However, I do tend to change my mind a lot about my career path, so I don’t want to shut out all other options yet. I’ve seen people say that IBDP workload is unbearable and I’m not great at managing coursework at the moment, but I do think that’s something I need to learn. I only do one coursework subject at GCSE which is PE so it’s not even much coursework but I have procrastinated loads. Then again I feel like that’s due to me not enjoying the content as much as I thought I would, which makes me consider IBDP since most people say it’s really interesting. I’d love the possibility to study abroad so it’s good that it’s international, but I feel like it’s less well accredited in the UK and there’s really not guarantee I can study abroad. I think it’s worth adding that I do care about studying and I get good grades but I understand the IB course is much more demanding than GCSEs and I do value being able to have a busy-ish social life too.

Previously I was set on A-levels but I’ve gotten into a sixth form which offers IBDP and I’m now considering the opportunity much more. My A-levels would be Physics, Maths, Politics and Spanish so I definitely like the idea of having breadth in my subjects. My main concern is that I won’t be able to get into a good uni course or that I can’t keep up with the workload. Firstly, I want to do engineering at the moment but I’ve heard offers for IB students are way harder to meet (the A-level ones are hard enough for good universities) and I don’t know if I want to risk it. However, I do tend to change my mind a lot about my career path, so I don’t want to shut out all other options yet. I’ve seen people say that IBDP workload is unbearable and I’m not great at managing coursework at the moment, but I do think that’s something I need to learn. I only do one coursework subject at GCSE which is PE so it’s not even much coursework but I have procrastinated loads. Then again I feel like that’s due to me not enjoying the content as much as I thought I would, which makes me consider IBDP since most people say it’s really interesting. I’d love the possibility to study abroad so it’s good that it’s international, but I feel like it’s less well accredited in the UK and there’s really not guarantee I can study abroad. I think it’s worth adding that I do care about studying and I get good grades but I understand the IB course is much more demanding than GCSEs and I do value being able to have a busy-ish social life too.

Hey, im currently an ib diploma student in the uk and honestly its a hard decision. Considering you want to do maths in the ib its actually harder than alevel maths and physics is also quite a hard subject. I would advise you to do ALOT of research for example, you have to do an extended essay and you also have to do at least 4 IAs essays (internal assesements) aswell as TOK. Additionally you will have to do CAS but this isnt hard. There are may requirements to getting the IB diploma like you cant fail your EE (apparently this is hard to do if you listen to your teachers) and you have to meet your CAS requirements. What you dont want is to be stuck in this demanding course realising you should've done alevels cause in all honesty its simpler and you end up at the same point as most ib students.
I picked the IB for the skills i would gain and also genuine interestin writing those numerous essays.
My highers are Biology, Chemistry and Psychology and i can honestly say im not finding the work too hard currently ( i mean i just started Year 12) i wouldn't say ive suffered a huge jump for my subjects but again this is different for my friends who are doing maths and physics as you've stated. I'm currently not regretting it and if you can't be bothered to read this long piece of text then just please weigh your pros and cons you can still work internationally with alevels.
SORRY FOR THE LONG ANSWER

Firstly I'd note that I honestly don't think that's a great A-level combination in general - I would suggest dropping one of the subjects honestly, if you did stick with A-levels (or swap one for FM if aiming for engineering). Taking 4 A-levels is usually not recommended unless two are maths and FM, and you don't get "bonus points" from unis for doing more than 3. You also run a real risk of stretching yourself too thinly and actually getting worse results!

Regarding your question I think it partly depends on what you want to do after 6th form. For STEM fields, A-levels may end up being better just as you can take FM (HL Maths doesn't compare to maths + FM anymore after changes to both curricula) and "stack" STEM A-level subjects which are cumulatively synergistic with each other. Yes being able to write decent long form prose is a very useful skill in those areas you will develop in IB but you end up ironically having a more narrow range of options in the STEM areas as a result. I'm saying this as someone who was studying in STEM fields after doing the IB too!

For other areas, ranging from the social sciences and humanities to things like medicine, I think IB does offer benefits in the breadth and intensity involved. However I do personally feel that the "equivalent" standard requirements for IB students vs A-level students aren't really commensurate with each other - personally I think it's a lot easier to get AAA or above than it is to get 38 in IB with 776 minimum in your HL subjects, for example. So you're kind of doing more work for less benefit in admissions (although debatably you may be better prepared for higher academic workloads by IB).

Universities outside of the UK widely recognize qualifications from other countries including A-levels. This is basically a non-factor. The reason it's "international" was to facilitate a consistent structured education for children of parents who move around a lot for whatever reason (rather than chopping and changing between different countries' school systems). I would not use this as a decision point.

In terms of social life that's really up to you - you can have a social life in IB, and fail to have one with A-levels! Equally I mean also, honestly what even is a 6th formers social life? Sitting around the common room eating crisps and chatting? You're not really losing out on a huge amount even if you have to cut that down. Plus in my experience IB usually has a strong sense of cohort, and a feeling of "we're all in this together", and is usually a smaller group as well, so you kind of have a premade community from the get go, which can be nice.