I've been on-and-off curiosity stream(+nebula) and dropout tv, the former for several science/tech/logistics related youtubers' longform content, and the latter for comedy. While I wouldn't call those categories especially niche, but I've grown to enjoyed their content more than current offerings from netflix and amazon prime to be frankly honest, and I'm all for it.

It seems vimeo found their niche(?) of a market providing white-lable OTT service, which I'd assume makes spinning up a streaming provider for a niche market even simpilier.