Yeah, this pissed me off too. I’m currently combing through iOS safari settings trying to find out how “allow videos to autoplay” was ever enabled (there is a setting for this in “accessibility” but doesn’t seem to fix this website at least so I’m still looking)
Sadly, autoplay-blocking seems to be even more of an arms race than ad blocking.
Apart from that, as long as this garbage takes up screen space, it's still not enough.
I hope that the person who invented the "sticky video" idea has a long and happy life, in a completely different job, completely separated from anything that has to do with marketing.
This is the dark pattern that I hate most on mobile by a 1000 miles.