I’ve seen this used on other Fediverse posts:

https://catbox.moe/

Imgur?

Honestly, Youtube is probably the easiest option because everyone already has an account and video hosting is expensive so it usually comes with caveats.

I’ve also heard about saint.to which could be an option

Personally I use peertube, the instance that I’m on allows 6GB of total uploads per user for free and you can pay for more space if you need more.