I found I could visaully block the pop up and use keyboard controls to still play a video. It did break navigating the page though because while I couldn't see it popup it was still there.

Revanced still works, not using it is just silly.

I’m able to play videos on my Samsung S9 with Firefox running with ublock. I never got a message.

I had this too, only thing that worked was clearing cookies and site data of YouTube, then logging in again. Another browser on the same account with the same uBlock settings worked the whole time, so I guess it's "device" bound not account bound. Since the cookie purge I don't even get the AdBlock warnings anymore.

I'm unable to watch any video despite uBlock instructions thing.