Actually, no I was not aware of it. I avoid TJC like a plague. Too hostile - and that comes from a guy who frequently comments on YouTube.

I have looked through that list and like juiceme, I did not find anything I would use or need

I have one reservation, though. This comment: "videos do not play". That is patently not true. I spend countless hours a day watching and commenting on YouTube videos. My Jolla is (still) indisposed and waiting for a cold restart, but the stock Sailfish browser on my Xperia X is what I use almost exclusively. There are some odd problems with responding to other people's posts, but watching works perfectly fine.

There are websites where embedded videos don't work. For example, BBC. They look like they still use Flash so I am not surprised. Nor am I missing it.

But yes, I accept the answer, even though to me it is a case of Schroedinbug

Again, thanks for the answer but that's a lot of advanced features WAAAAAY beyond what I would even consider using, or even know they exist, let alone know how to use them. First party isolation? Smart referer header? uBlock origin? Aggressive mode? Are you speaking in Elfish?