That's just 1.5 museums per town. Tiny towns have tiny museums. Like a small town i went to once had a "lock and key" museum and it was just the history of locks and keys. Very niche, pretty small. I think they weirdly also had like history of telephones and maybe record players in there? Like a decade ago, so i can't remember.

But also, most actual cities have multiple museums, or even over a dozen, so a lot of small towns don't need any to make it to 30k.