I go to try out different systems or to play systems my regular group doesn't play. Also, to remind myself why I have a regular group and how fortunate I am that they are mostly sane and adjusted people.
I always shied away from gaming with strangers or even making friends at the game shop until a few years ago when I was looking for a table for FFG’s Edge of the Empire (this was well before Genesys). There was one near me and I played there every week for years. However, there was one session where a player made a min-max melee build that was able to go toe to toe with one of the DM’s scary NPCs and he went off on a huge tangent about how he would never allow such a build, etc. It made me really uncomfortable so I stopped going after that. Then COVID hit shortly after and I haven’t played a game at a shop since
Honestly, it's a niche service for an already niche hobby. Why would I leave my house, where all my snacks, drinks, prepared game materials, minis, computers, and audio devices are, to come play at a noisy expensive card table somewhere else? It's only really going to appeal to people who, for whatever reason, can't play in anyone's home, or aren't welcome at the tables of anyone they actually know.
It's never something I've done frequently, even before COVID. I've been to a couple of game shops, but often our group would use public or semi-public spaces like library rooms or common rooms, when not playing at one or another players' house. That's before we went fully digital.
I play with my group online and we have a lot of fun (very rudimentary set-up: Discord to talk to each other, Paint.net to move pieces across a map downloaded from the internet).
I also play Adventurers League with my brother in a game shop, but I only go to spend some time with my brother. I find Adventurers League really boring and playing with randos doesn't excite me.
When a friend of mine owned a game store, we'd go play at the shop every week, sometimes twice a week. Since he closed though, I haven't played in public anywhere. I would probably still go play at his store if he hadn't closed.