It's depressing how many are institutionalised into a 9-5 with all the disadvantages that brings. Can't be talked out of it. Like lemmings.
9-5 traffic worse than ever.
On top of that we have all these companies telling everyone they need to return back to the office now, taking away WFH.
While I am very much in favour of flexible working arranges and hours, and especially WFH and I take full advantage of the flexibility my employer offers me and enorage my team to also leverage this flexibility, the realty is very few jobs work OK in complete isolation. Software development for example - while often coding is best done with a few hours completely uninterrupted in a quiet environment which is often best done form home , it also needs collaboration with other engineers, discussing. architectures, API contracts, co-programming, code reviews. And most places emply Agile management for software which directly endorses co-located development teams and regular rituals., promoting communication over documentation.
So to do this you need some structure over working hours, even if there is flexibility you need to ensure god overlap and be cognizant that is someone works i a different time zone or doesn't get online until e.g. mid-morning then this can leave other developers blocked. It is also clear that communication is best in person. Slack and zoom etc is definitely reasonable, but nothing beats a huddle around the white board hashing out a new architecture , or chit-chat over a coffee to agree on next steps