A couple of points for clarification:
We didn’t ask for full time return, just 2 days a week. Several people have not come in for almost a year since we did that.
We know who is productive and who isn’t. Mostly it is the ones working remotely never coming in. The most productive tend to be those on hybrid schedules.
We have found ways to monitor how people try to game the system remotely. High incidence of mobile only usage for Microsoft Teams for example. Little proactive contact, only reactive when you reach out to them. Which indicates many are only making themselves available if called at times, not doing enough proactive work.
We have noticed that deadlines are met less frequently for collaborative projects, when a high percentage are remote workers.
Mostly it is the ones working remotely never coming in that are the least productive. (corrected previous post).