These are typically junior bankers working on M&A/IPO deals. The ones working on the desks/trading will have much more moderate 45-60 hour weeks with little/no weekend work.

The salaries sound high - but bearing in mind that you will need to live within very close proximity to the financial centre of the city (London City, Canary Wharf, Wall Street etc) you do not end up with much spending money at the end of the month.

You may well have a comparable salary as a relatively junior FAANG developer with a lot less effort.