Does economics at a specific university matter? e,g. southampton

- I am trying to go into banking or corporate finance or any other finance job tph.
I have offers from southampton and i got rejected from my 4 other unis.. so I can either take souhtampton or sign up for clearing??
but clearing is risky i could get no offers at all and have to gap year doing nothing.
southampton isnt even bad its pretty good it was top 15 for econ now its in the 20s.
would firming southampton hinder my chances at getting a good job in the future...??
im predicted 3A*s

If your aim is investment banking or management consulting it doesn't matter what you study, but it does matter to a point where you study it - namely at a target uni (typically held to be Oxbridge/Imperial/LSE/UCL/Warwick). Doing economics at a non-target uni is probably not going to be as helpful getting into that sector as doing any other degree at a target uni.
Particularly as you are predicted 3A* if you are resolutely aiming for investment banking I'd suggest just applying to another course at those other unis. You could just as well do e.g. classics, viking and old norse studies, Egyptology, anthropology, history, politics, chemistry, biological sciences, materials science, etc.

why does it matter ?? if im doing econ at southampton what jobs or what sectors would be more likley for me to get? is there still a chance i could go into investment banking or consulting.

so i could do like an easy 3 year course not related to investment banking or maths and still get into those firms? just bcs of the uni i go to??

Because investment banks for whatever reason maintain their list of target universities and preferentially recruit from them (and hold more dedicated networking and career opportunities on campus for those unis). It is if course possible to get into investment banking from a non target uni (usually a semi target though) but you may be more likely to be passed over in the first filter/sift of applicants (and it may be harder to get the relevant summer schemes/internships to be able to apply successfully to grad roles).
Economics itself is not really that related to investment banking. Most of what you'd study is either well beyond what would actually be needed/used in investment banking or not relevant. Economics is relevant for roles in economic policy/economist positions.
I'd also be careful about assuming other courses are "easier". They may involve different skills which may be easier for you. But the overall difficult level will be comparable across different degrees at the same uni. Just because a course doesn't involve mathematical elements doesn't make it "easy".
But in any event yes. Investment banks don't care what subject you study - you could do whatever you find interesting and provided you get relevant internships/summer schemes, prepare well for the interviews and assessment centre exercises etc, at a target uni, you have as good a chance as someone doing economics at a target uni.
The preponderance of people who did economics at target unis going into the field is by all accounts more reflective of self selection out of that sector by those doing other degrees (as e.g. a chemistry grad may prefer to explore scientific positions for graduate employment; an archaeology grad may prefer looking at work in the heritage sector; a linguistics grad may look for technical work at tech companies with search engine and AI research; etc). People who want to go into investment banking from the start just tend to choose that degree and then pursue that as being very career oriented individuals, but plenty who get to the end of their e.g. biology or history degree may decide to pursue that route after doing an internship in the sector.

wow, greatly summed up, thank you so much. this is a lot of new and vital information.
so im guessing- rejecting my southampton econ offer and going into clearing for a random degree at ucl//LSE would be ideal if i want to go into finance sector?

LSE doesn't participate in clearing and UCL has not historically participated in the main clearing process (they have in one year recently participated in clearing plus where they will reach out to eligible students to make an offer if they choose). The only target uni I know which has been in clearing before is Warwick sometimes for some courses.
In any event, the above is specific to investment banking/management consulting. For other roles in the financial services sector including e.g. accountancy, actuarial roles, etc, any uni is typically fine. If you are resolute on pursuing investment banking or management consulting specifically then taking a gap year to reapply to a target uni may be worth considering.
It's worth keeping in mind though that even if you go to a target uni and get relevant internships/summer schemes etc, this still may not translate to a grad role at an investment bank or management consulting firm. Equally it is possible to go into those sectors from non-target unis, but it would probably make it harder/less likely. Ultimately its up to you what direction you want to take with that.

oh okay thank you so much, taking a gap year and not going to southampton? but im not even sure i want to do investment banking - i would like to explore finance roles. I might accept my offer at southampton - i know people who have gone there and landed internships at firms? but again your right this is a rare case. A gap year does not sound ideal.

why does it matter ?? if im doing econ at southampton what jobs or what sectors would be more likley for me to get? is there still a chance i could go into investment banking or consulting.