publishing it on YouTube is perfectly understandable, since the purpose is to reach people that are not already on the Fediverse.
However, having it mirrored on the Fediverse for use by people there would also be nice.
Could you let us know what problems you encountered with the platforms you explored?
I think having your own PeerTube instance would make sense but you could also ask tilvids@mstdn.social whether they could host an account for you in the meantime?
https://tilvids.com