What if he(and others like me) believe that working in-person really is truly necessary for accomplishing great work?
Well, it's his (and your) right to be wrong but that's a belief that was already on very shaky ground before 2020 and has by this point been absolutely proven wrong.
Unless your job actually requires physical interaction with or proximity to a thing or other people it can almost certainly be done equally well remotely.
Processes may have to be adjusted to account for remote workers and even the way people work when working remotely, but almost 100% of jobs that take place at a desk in front of a computer can and should be allowed to be remote.
The biggest thing that doesn't work in a remote environment is micromanagement, so bad bosses who feel the need to micromanage hate it, but those people are terrible so if they don't like it that's a good thing.
Not all problems require new or genuinely creative solutions either. And it seems really difficult to try and measure the creative output by individual contributors at any given company. You have no way of gleaning the micro decisions or solutions that people come up with for their internal issues. So this doesn't seem like one could "easily argue" this point at all, in fact it seems quite difficult.
Are you suggesting that product offerings are less creative as a whole? And if so, again what metric are you using to arrive at this conclusion? And are there really no trends of this same metric before 2020?