We are discussing this intensively at work, so naturally, I summarised this on a Power Point presentation, which was well received.
My conclusions were pretty banal, and have been covered on the thread already. The key thing, as Ciderglider and others have said, is that what works for me, doesn't work for you, so the key thing is that it should be fully flexible/optional for the employee.
A common conclusion, is that for technical discussions, whether WFH or in-office, everyone prefers to be able to use SKYPE or TEAMS to be able to use their own screens, so all meetings should as far as possible, have an option to dial-in.
Another thing, is that the advantages for the employee of WFH, can also be built into a case for the employer - no wasted time commuting, less absenteeism due to catching the 'flu on the bus, less expensive office real estate needed for example.
Personally, I now find it extremely difficult to concentrate in the office when I can hear people around me talking. Maybe because I'm not used to it, but I am definitely less effective in the office compared with WFH.
But we have certain measurements that indicate we need to have some amount of face-to-face contact in the office, to maintain a certain level of creativity, to spark off each other and so on, and although I prefer to WFH, I can see this happen when I am in the office.
But how much is enough?