Video embeds tend to be especially fragile however since they're often implemented by gluing together a relatively large number of third party services. Any one of the services goes down or changes the API and the whole thing breaks.
Ask any uMatrix user how much fun it is to get a video to play on some websites and just how much external crap you have to allow before you see the first frame.
That and Facebook container. I could not get slack to work until I allowed slack access to Facebook because I had to re-authenticate. Even though I don’t use Facebook I have to allow slack to access it at least to be able to authenticate to a different authentication source.
Ask any uMatrix user how much fun it is to get a video to play on some websites and just how much external crap you have to allow before you see the first frame.