I almost never click a video by someone I don't know these days. It's almost always a waste of time.

Same here, generally, but I think there are a tiny few people who have a legitimate reason for using TTS. For instance, those whose English skills are lacking, or who have an accent which some might find distracting. Or a person who is self-conscious about their voice but still has something to offer, or maybe those who legitimately can't speak at all. Hell, I support anyone who could narrate but doesn't want to put their voice out there for privacy reasons, or to keep it out of the public space where it will inevitably be used as training data.

I'd still rather listen to the human, because I can't stand any of the "AI" voices, especially those that are used on every fucking tiktok (I stay away from TT, but unfortunately the voices are pretty ubiquitous). It might sound silly but I'd prefer good old Microsoft Sam to the any of these new voices.

One channel I found recently for coding-related topics uses TTS but before I got annoyed enough to close it, I realized that the script was probably hand-written, just narrated by a machine. The video was highly informative, and I walked away having learned some new information. For the curious

Something that sucks about this new wave of TTS is that we get some odd errors in pronunciation that probably wouldn't be there if it was spoken by a human. A missing comma or other punctuation errors will pass a spell check but end up sounding really strange due to the broken inflection. Uncanny Valley stuff I suppose.

AI thumbnails are utter garbage though. All polish, no substance, no love for the craft.

Yup. I think the worst offenders are the videos that are just Wikipedia pages with still images and an AI text-to-speech robot voice. It's the world's laziest form of "content creation" and I always downvote them.