There are channels I watch regularly because they cover topics I want to see covered and I've seen their previous videos and they met my expectations. Then they'll use AI thumbnails while focused on finding the right topics and thinking about how to present them. Some of them are clearly letting an AI write the main part of a script and reading it off (while still being clearly a human doing this and not some weird TTS monstrosity). It annoys me to think that I'm incentivizing people to do this, or letting The Algorithm get the wrong idea about the quality of these shitty thumbnails that don't matter now that the creator is in my feed and I can read the video titles.

(I also end up watching a fair bit of stuff where the thumbnail is literally just a random frame from the video, which lets me know the subject, and the title is some clickbait nonsense that I don't care about. There are a lot of ways for this stuff to work.)