They need to stop showing people the upvote and view COUNTS. Behind the scenes they can still use it to make recommendations.
Those numbers are pseudo signals of quality to people who encounter content they have never encountered before.
Even when they have doubts that are watching something unhealthy the mind goes "well if the rest of the world thinks this dumbass is important I better pay attention..."
If a dumbass hurting people on video gets 10 million views other dumbasses worldwide automatically get triggered looking at the count. "hey I can do this maybe I should run for President..."
Remove the counts and you remove the pseudo signal of quality.
That only works for rational people.
Also, I'd say people turn rational or irrational on their own choices.