A very left-leaning friend of mine (I think of him as my Bluesky friend, the same way that @siggy47 has an MSNBC friend) ranted about this to me (well, to our group chat) today. The gist is that the Online Safety Act that the UK has such strict requirements that one person can't manage all the potential requirements, and the costs are too high. Note that the person running that forum is trans and a cyclist -- I'm sure there are plenty of people who are one or the other who aren't on the left, but the combo makes it a lot less likely.

The post my friend pointed to that linked to that site was this one, and it pretty much sums up how the left are feeling -- they view this as something that only big businesses can handle, so any small forum will have to shut down. This is how libertarians are born.