Because bandwidth is super expensive.

Unless you're a very big player handling excessive amounts of users, the bandwidth involved doesn't need to cost an arm and a leg.

I can see why private individuals might prefer something free, but for organizations or other professional actors which are publishing high-quality video-productions, they already have a budget, and frankly the BW cost is probably going to be the smallest expense on their list.

And when they risk losing their platform and audience at a whim (as we've seen Google do repeatedly to certain types of organizations over at YouTube), I can't see why more people don't consider other options which leaves them in full control over their own content.

Because that is a bare minimum solution that only works via web. YouTube provides native clients for mobile, TVs, consoles, etc.

Also, because Google pays you to host your videos, if you are willing to allow advertising.

I mean, given what Blender is, having tutorial videos accessible by anything other than desktop browsing isn't a hopeless or horrible thing. Every Blender user has a desktop or laptop (or has modded something to heck and back in order to run Blender), so having it be somewhat difficult to access a majority of their videos by mobile, TV, console, etc, might not be such a big loss.

IME mobile works fine too, so it’s just TVs and consoles losing out (and there’s always chromecasting).

I say it’s a more than good enough delivery “platform” for this kind of stuff.