I think you're absolutely right - what's never taken into account are the bits of work remote workers do out of hours, whether they're supposed to or not.

An extra 5 minutes here and there, moving around breaks to accommodate meetings or just focus time, and communicating with people in different time zones too - something many of us do a lot of.

If I were forced back to an office, in the time before I quit I'd be strictly 9-5 and my productivity would absolutely plummet as a result.