I do fine and agree school can be a nightmare if your face doesn't fit.
I was never "seriously" bullied, but group dynamics, status jockeying, people being over-competitive, can be horrendous.
I got 4 As at A level and a first class degree (preens but no-one gives a fuck ;'-) ) and tbh could have done the work at home part time or remotely.
All I got was feeling slightly awkward, no-one I stay in touch with as an adult, and feeling quite emotionally claustrophobic and that something was wrong with me.
For sixth form, I was pressurised into a fairly "high-achieving" sixth form at a single-sex school and my mental health struggled NOT because of the work but because of the low-level sense of menace, teachers who would randomly target one person unreasonably and write spiteful reports, that kind of thing.
My "group" was a few very neurotic types who were very competitive, which just exacerbated my sense of loneliness.
It felt like I was there as it "looked good" - the teachers weren't that kind or emotionally mature, tried to collect us "top set" types into a group, and insisted if I was socialising with anyone else I was "rebelling".
But this group really was very passive-aggressive and competitive...there was no sense of camaraderie.
I totally agree school can be a great (or at least neutral) experience for people, but I'd say for significant proportion it can be negative.
The thing is, I'm not a hugely "alternative" type either (whatever that means). I am and was a fairly standard, low-key human being.
I didn't want to be alpha female or Head Girl, just have an OK social experience with nicish people I got on with. But this didn't happen.
So all those arguments about school being "good for socialising" just aren't true.
I have made peace with my past, but if I could travel back in time, I wish I'd gone for a more relaxed environment for A-levels (an adult FE college or registered as an independent student) and worked or set up a business the rest of the time.
My bank account would have thanked me too!