Those who can't see a significant change in quantity also have selective memory

Maybe that's true, But I think before LLMs became common, people had more distinct ways of expressing themselves, low-quality for not. Now, a lot of online writing feels uniform and I think that is worse.

The quality hasn't changed. The volume has. It used to take real human time to create garbage. There was value in that. Someone though "Hmm, what worthless thing can I do? I know! I'll make people online mad." And then they spent the time getting someone else's goat. It was great. A good balance, spreading lies took some minimum effort. Now we have automated garbage. And the flavor of the garbage is: gaslighting people with an illusion of community. We've empowered the trolls with an infinite meme-o-rater while ignoring the real human time spent unwillingly sifting through the ever increasing pile of worthlessness.

The world does not have to get worse. We're letting it though.

The comment that you are replying to does not mention a ratio.