I think it's starting to happen

one thing I would like to see is niche sites (e.g. forks of wikifreedia's code) that focus on a topic

the first one I thought of was medicine, which is a highly censored topic

all it would need is a:

* domain name

* UI that matches the topic

* filtering all content via the niche site's choosen category

launching a "nostrmd.com" is basically a weekend project