Is this even a problem?
I mean its been what three decades of internet without age verification and people can't really point to specific issues with it, just sort of gesticulates that they must be there despite the millenial generation being about as well adjusted as any other. I would say seeing a pulverized squirrel on the road with the brains scattered about in real life is far more traumatizing for a child than seeing even human on human violence and gore on the internet. Movies have done a lot to desensitize that sort of thing when it is served on a screen versus in real life where you can smell it and walk all around it.