I don't really know what the answer is either, but you're right. The extremes we see in porn today are very concerning. The things you listed shouldn't be in main stream porn and need consent and open conversation outside of sex before adults who understand what they are doing actually do them. I find it crazy that it's made its way into mainstream videos and blame the idea of things having to be ever crazier, ever more extreme to get attention.
But blocking teenagers off from porn, or trying to, won't help anything. I think we need to be open, honest, and have real sex education. I also think these things are why some sex ed now includes actually how to have sex rather than the physical components. But that serves to give the prudish more ammo of how sex education is porn itself even when meant to be purely educational and combat these extremes people are seeing. There's so much nuance to the issue that I think a lot of people get bogged down on one part or on their own preconceptions.
It's also like when you ignore that video game makers research and develop how to make their game as addictive as possible and ignore an entire thread talking about it. Oh wait...