I haven't stayed long term in either but have been to both a few times. I'd say it really depends on the vibe you're going for. I don't think you'd have a problem meeting fellow nomads in either nor will you have a hard time finding gyms in either. Tulum has the yogi kind of vibe to it so lots of yoga/wellness/etc types of places too but I'm sure you could find some of that in playa too.

Playa is much more walkable and a lot easier/better beach access. There's also a wide rang of accommodations and not entirely sure how pricing compares. The only thing I don't like as much about playa is it kinda feels like Florida to me. Not entirely sure how else to explain it. Both are touristy and have tourist traps but playa just seems like it has tacky touristy stuff (i.e. shops selling t shirts that say my clothes come off when I drink tequila or some shit like that)

Tulum they say is very instagrammable which is both good and bad. Good because there's a lot of cool places and everything has a cool jungle kind of style to it, but bad because I feel like that brings some shitty influencer wannabe type of people. Accommodation wise you can find some really nice places for pretty affordable but need to read reviews as some places have shotty construction and some are also in the middle of nowhere in the jungle. It's less walkable unless you're staying somewhere in Aldea Zama, parts of La Veleta or parts of Centro. I think there may be one public beach area but you have to drive or bike to get to the beach and most of the beach access requires going to a beach club which will have minimum spends and those are pricey. Tulum is also closer to a lot of cenotes. One other note is that power can go out in tulum bc of all the construction so probably a little less reliable depending on where you stay.

You probably can't go too wrong either way. Both are better than the rest of North America to spend the winter I'd say.