there is, maybe, a market for more specialized, niche platforms...but it's a huge maybe.
nebula seems to be doing very well, but again: highly specialized content, and a closed/curated platform.
other than serving video content, it has little in common with yt...hence the big "maybe"!
and there's been a few similar attempts in recent years, which i don't think really went anywhere either...
yeah, .... that's fair!