"[In Q3 2018] YouTube removed about 1.67 million channels and all of the 50.2 million videos that were available from them. Nearly 80% of the channel takedowns related to spam uploads, YouTube said."

https://www.businessinsider.com/r-youtube-under-pressure-for...

The remaining 20% were apparently taken down due to nudity and other policy violations.

To be clear: I have no idea whether they're profitable or not. Just pointing out this article.