I built a tiny, kinda crappy multiplayer web game a few years ago (
https://manygolf.club/), and while it's mostly dead now, it was relatively popular with 5-15 active players at any time for a few months (I know, small potatoes, but as someone who had never made a game played by _anyone_ outside of friends and family before, it was cool to see).
I noticed one of my biggest traffic referrers appeared to be from some kind of school proxy, and the most common Google suggestion for "manygolf" was "manygolf unblocked", so I imagine it is a lot of bored kids with locked-down devices. I also still get an occasional email every now and then from a "game portal" site that wants to license my game in some way, so I guess that stuff is still a market unto itself.