Gen Z here, can't speak for others but I find that I tolerate less crap than some of my older employees when it comes to staying at the office late.
It boils down to the fact that I don't work for free, so if my boss expects me to stay late after work I expect to be paid for that work. Some might think this makes me "lazy" or "entitled" but I stick to my contract and work my butt off between 9-5, not doing unpaid work in my freetime does not equate to laziness or a poor work ethic - my work ethic is fantastic during the hours I'm contracted to work. It's also fantastic during the hours outside of 9-5 if I am paid for that overtime.
Expecting my employer to pay me for additional work that they ask me to do for them does not make me entitled. I've also seen older colleagues work overtime for free on several occasions and get nothing for it, no credit, no promotions, no payrise, it doesn't serve them to donate their free time and work to the company but they feel as if it shows good work ethic, whereas I feel it just shows poor boundaries and the ability to be exploited.
I have been promoted twice since my time at the company and that isn't due to me donating my free time to the company, but due to working hard, high productivity, taking the initiative etc. I consider it an old myth that staying late after hours progresses you in the workplace when actually in my experience, it's the value and productivity you present to the employer that can get you the promotions. If an employer values how much of my free time I'm willing to donate and how much work for them I'm willing to do for free over how hard working, productive and helpful I am between the hours of 9-5, they're not an employer I'd consider working for as to me, they have their priorities wrong.
That isn't to say that I don't stay in late to finish something off sometimes, but that's of my own choosing as I like to make sure all my tasks for the day are done and I don't expect to be paid when I choose to stay in late, but the times we have been asked to work late into the evening I have asked to be paid for my time and my employers have always honored this. I've had colleagues who accept the same request but do not ask to be paid for the work get annoyed at me for my "entitled" attitude - I think it's entitled of any employer to expect them to work for free, and it isn't entitled to ask to be paid for work that is expected of you.
I am, however, very responsive to correction/criticism, often encouraging it, and have worked my way up from the bottom by working very hard so not all of the stereotypes apply to me. I have worked with others my age, all but one shared the same hard-working approach and the one who didn't and couldn't put their phone down didn't last long. I do agree that there are differences in every generation, but not all of them are necessarily a bad thing.