The problem with most office mandates is that they just require a person be in an office, any office. In my experience, this means it is very possible to be in an office with a bunch of people that do completely different jobs, so all day is spent on the phone. If I need to be on the phone all day anyway, I might as well be at home where it’s quiet, so I can hear people, they can hear me, and there aren’t any distractions.
Forcing people to relocate just to sit alone in a cubicle on a phone all day doesn’t improve productivity, it just makes people upset.
I do think meeting people in person has a lot of value, but office mandates aren’t the only way to handle that.