It's going to be different for everyone, but for me would be:

- More schedule freedom. I hate being forced to stay here from 9am to 6pm. What if today I want to get here at 11am, and only leave at 8pm? I'm still working the full 8 hours, so what's the problem?
- Actually work with what I want and enjoy doing.

To be honest, that would be all for me. This is all (I think) I need to be happy while working.

@Jilano where I work right now, no one calls me, if they need to contact me they will come talk to me in person or, if they can't, email me. Since I'm talking about this company in particular, it is very common that someone will call (not me, but my co-workers) in the middle of the night with a problem. "outside working hours" don't exist for some of them. I think this will be my future, but I'll see when I get there.

Obviously, if I knew someone needed to talk to me at 9:30, I would be sure I was there before that time. If not, I might still take the call and go to work before what I was planing that day

Emergency: phone call 24h
Non-emergency: email/slack

Jobs prone to emergency calls should not follow the 8h/day schedule.