It's a lose-lose scenario for content providers. Lose if you censor (https://news.ycombinator.com/item?id=19274406), lose if you don't (https://www.reddit.com/r/videos/comments/artkmz/youtube_is_f...)

This isn't quite safe harbor. It's not like the app was removed for one user posting one bad content. If what the poster above said is true, it's closer to if an app had a user who regularly broke the rules, and the app refused to ban said person.

I'm not sure what you mean by justification. I think I simply lay out some context and a set of conflicting perspectives.

That said, if you don't want Chrome and Firefox to be content aware, then you should argue that safe browsing should be eliminated from Firefox and Chrome. That is a self consistent position, but it may not be consistent with e.g. avoiding dramatic growth in botnets, ransomware, organized crime etc.