For YouTube, this already exists and I‘m using it. The extension is caller DeArrow and aims to reduce sensationalism via crowdsourcing, though I wouldn’t be surprised if top contributors are bots using LLMs.

Man, that before-after slider on the home page makes me so sad... YouTube used to just be random people sharing cool stuff, and those de-sensationalized titles really brought me back to that time for a second! Cool stuff.

For people like me had tried it in the past and found it annoying, note that it now has a 'casual' mode where it only changes the truly useless titles and leaves reasonable ones alone.