I think the thing is called "Red" in some countries although I did not see that marketing branding term on this occasion. I am thinking of adverts in the programmes btw, not images on the site.
I look at YouTube in the Youtube specific app on an iPad. I am not sure that it works using a normal web browser on iOS and it may be you have to use the app.
I have an excellent ad blocker for Safari, 1Blocker X, which is very powerful and customisable. It does not affect dedicated apps though only Safari.
iOS is very locked-down and ad-blockers are only now possible because Apple designed an engine (I think) and published an interface whereby ad-blockers can provide a database and drive Safari, from my best guesswork. I may be wrong, but it seems to me that Safari does the blocking and the third party app tool tells it what to do and is responsible for the quality of the database. That way, I suspect, they have made it so that an ad-blocker can not screw Safari up or introduce bugs, slowness or battery guzzling into Safari's guts. Others who actually know what they are talking about will be able to deny or confirm this theory. (If this idea is right, it is vaguely analogous to the 'mini-port' or 'mini-driver' or whatever it is approach to device driver writing, and enforced.)