Not for deep interests, but you know like that old song about someone’s favorite things where the examples are all like copper kettles. Where you might write a few sentences about the little thing you like.
Then finally you can compile a list of posts somewhere so you can have it all in one place
You could totally create a new community too, but I think it will take more work to get something like this off the ground. The moderators might be posting a lot of the content early on