I wouldn't work 50-60+ hour weeks. I'm 36 now with 2 kids. I've come to realize that all that time I put in really didn't do much at all for me. I'd much rather have my free time back then make someone else rich.
41 with two kids, all that time spent working should have been spent experiencing the world and having a lot more fun.
I think a combination of getting more senior at work and having kids reduces your choices in how you can spend your time (To be fair it opens up new options as well). It highlights the value of your time and how little you got in return for it when it was abundant.