I don’t know about that. I work a office job and often deal with people from all over the world. Getting everyone online at the same time for a meeting or phone call is really difficult.
Yes I can send emails but sending an email and not getting a response till next morning really eats into timelines.
We can have video meetings and phone calls and share screens so I fully understand WFH and support it. That said having no requirements for work time I think would be really bad.