Under ideal conditions, I believe in person is optimal. There really is a sort of collaborative emergence of ideas that I don’t particularly find online, in honesty. The issue is that conditions are almost never ideal, and under non-ideal conditions employee well being and efficiency is much better under WFH.
Out of 10 who say they'll quit maybe 1 actually will. And when they do there will 1000+ waiting to jump at a chance to work for Apple - under ANY condition.