It's an ad supported video platform that will give data to google, advertise your competitors to your customers, distract your customers from your product by being an entertainment social network site, have relatively poor analytics, etc. It's a non-starter for many businesses.

But of course not using it only makes sense if you can monetize your videos yourself by selling it or another product.

When you upload on YT you are the product, YT sells you and your data and they profit. What vimeo is selling is hosting, saas, and bandwidth. They dont' profit at all except for what you pay them. vimeo comparatively to CDNs and SaaS hosting providers have a decent price. If you don't think so then hire someone to set up cloudflare stream and your own website.

Youtube is ad-supported. You can't upload videos more than 15 minutes long without letting Youtube put preroll and mid-roll ads all over them, and the only access-control method it supports is "unlisted", where anybody with the URL can see it.

Creators don't want to force their paying Patreon supporters to watch ads for content that they paid for, and that can be leaked to the whole world if somebody merely ctrl-vs a bit of text.