A lot of this comes down to the culture of an organisation of a 12 hour day vs a 4 day week. If it is a 12 hour day, and 90% of the people like that or want to do it as they know whats in it for them then great. If people know this, accept it and stay then it will become part of the culture related to ways and hours of work. Investment banks come to mind here.
If it is a different type of firm with a different type of service or solution where productivity is as strong across 4 days vs 5, then this can work as well.
There are businesses that will survive and even thrive with 4 day weeks. There are some that will struggle. As for expectations around a 12 hour day…if you enjoy what you do and know this is how it is to get the rewards I want and learn the things I want to learn, then it’ll be worth it for some people…at the time.
It may only be in hindsight they may wish they had more time for other things in life vs. money.