yes, many. Subreddits are sticky and it s almost impossible for someone to start competing with the medium-to-big ones , because the 'obvious' names are taken . This is especially true for countries / cities / brand names. As long as the mods are not completely crazy, there is only one word for 'politics' or 'europe', and users will not go to a new sub just because the mods are better.
If they were individual internet forums, people would just leave instead.
Reddit acts as big single-sign-on that heavily biases users towards its existing subreddits. The fact that reddit admins still allow a small group of people to moderate hundreds of subreddits for decade+ is proof of that. If they cared, they would mandatorily recycle them
4chan? I'm not sure they do anything but remove child porn based on the fact that I've never seen it there, thankfully. Maybe Gab or communities.win? I don't use those two enough to know. Twitter post musk? But even there I've seen people complain. It's a shame because reddit used to literally advertise being a free speech platform.
If they were individual internet forums, people would just leave instead. Reddit acts as big single-sign-on that heavily biases users towards its existing subreddits. The fact that reddit admins still allow a small group of people to moderate hundreds of subreddits for decade+ is proof of that. If they cared, they would mandatorily recycle them