Also, I believe that, like official job postings, a lot of "Who's Hiring" posts are just kinda-serious fishing expeditions. A lot of companies say they're hiring but in reality it's because they always have their bait in the water, waiting for some outlier good deal on a top talent, but otherwise not really hiring.

EDIT: The same is probably true for job seekers, too, now that I think about it. As another commenter noted, a lot of people are being frog-marched back to physical offices at gunpoint, and are probably low-key fishing for a sweet remote-only gig.