@sterophonick Most likely not; sites can't access any data about other sites by design (they're isolated for security reasons) so there's not really a way for one site to know whether stuff is playing elsewhere.
It *is* possible to synchronize such information between different pages on the same site; I believe that's usually done through service workers. And if you're the one embedding the YT player on your own page, I think it has some events you can listen to too, though it's been ages since I've looked at that.
@joepie91 i have and embeds in my site. the youtube embeds are harder because of that though