> I understand that they can be made to autoplay with no controls, but I don't even want the possibility of them being paused.

Your opinions are just that, and usually overridable by the client. The client could even strip your media entirely.

And gifs are pausable (used to be ESC though apparently you now need extensions).

> This way the format has no choice but to behave as expected across everything.

I've got bad news for you: once it reaches the client you're not in control anymore, you can only suggest behaviour.