Being primarily remote makes my days more predictable. I live by the calendar and save the few urgent matters there aren't much of any ad hoc things happening during my workdays. Even if it's not meetings I tey to schedule my tasks in my calendar as well to keep on track of what I need to do. Reserving slots for important tasks also ensures I actually have time for those as otherwise people would see a free slot in my calendar and book a meeting there.
At the office it's quite different. Sure I do have meetings on those days as well, but I try to prioritize meetings that are face to face at the office for those days. Other than that it's all ad hoc things. Talking with people, catching up or helping them out. I feel like many of those things don't happen online. It rarely happens that somebody ask if I have a moment to talk with them when I'm at home. It's always calendar invites and people don't usually bother to book those for small things. Of course the smallest things can usually be dealt with via chat. But ot would be nice to have something in between as well.