I suggest a different anecdotal study: asking how WFH is done. I mean, on one side how the worker's home is organized (dedicated room, with proper furniture etc vs a craptop in the bathroom) on the other how the company organize the remote part (VDI vs real remote collaboration, for instance).

That's IMVHO and without tangible proof give the best feedback witch is: IF the worker have a good place (and a calm family situation) AND the company is organized for real remote work nearly 100% want to be remote. If not...