Honestly no offence meant, but you won't be very good in your connections. You won't know the right people, the alumni or professors or generally all the actually important people that will give you massive leg ups if you want to start a company.

As for learning? Your peers won't challenge you, you'll be exposed to easier lessons, to easier concepts, you won't really get challenged at all. When I was keeping up with this stuff, in the UK the shit unis taught Java, the good ones Lisp or Python. The whole ethos is different. A friend of mine got a 1st (best degree in UK) from the 2nd tier University he went to.

But he couldn't remotely handle complicated code written by our literally genius colleague (I've honestly never met someone so insanely good again in 15 years). He was not anywhere near 1st material in a real top-tier university. He would have been lucky to get a 2:2.

I know someone who did the 2nd tier route and who is genuinely good. He, perhaps like you, is the exception, not the rule.