I've often found the contrary - they add a lot of noise into the signal. For example, the gify bot encourages people to post response gifs to response gifs, creating pages of nothing but pure crap, making content harder to find than the proverbial needle in a haystack.

I don't need web pages expanded in-place, it pushes content off screen. I don't want CI/Jira/Pagerduty spam constantly dinging for my attention. I don't want random gifs. I don't want YouTube videos expanded and started automatically.

Maybe there's a good bot out there, but I haven't seen one yet.