Someone else has already made the point that working long hours is not exclusive to high earners.

Regarding the hours, pay and age bracket as to when you'd get circa £80k, it also depends on the profession.

I'm a solicitor, 27 yo and just got a pay bump to £85k, but I'm even underpaid given market rate for my field in London. If I moved to a firm outside of London to the regions, I will get paid significantly less but the hours won't be significantly different especially in a high tier firm.

I won't probably be able to afford a house in London yet, but I have other priorities. London firms offer higher pay, faster progression and more opportunities including working abroad. Working for a City firm also gives you a better chance of getting into great legal in-house opportunities that pay well and have more sociable hours like Revolut and Google. Given my CV, I can eventually move outside of London and negotiate a higher salary.

People have different priorities, and although expenses, work hours and work pressure might be higher/worse in London, these high paying jobs likely set you up for the rest of your life so these people are not "worse off".