I've noticed this for a while, when I accidentally click on YouTube Shorts. (I want to avoid it, because it's brain rot, but YouTube keeps enabling it and pushes it hard in notifications).
It's most glaringly obvious in TV shows. Scenes from The Big Bang Theory look like someone clumsily tries to paint over the scenes with oil paint. It's as if the actors are wearing an inch thick layer of poorly applied makeup.
It's far less glaring in Rick Beato's videos, but it's there if you pay attention. Jill Bearup wanted to see how bad it could get and reuploaded the "enhanced" videos a hundred times over until it became a horrifying mess of artifacts.
The question remains why YouTube would do this, and the only answers I can come up with are "because they can" and "they want to brainwash us into accepting uncanny valley AI slop as real".
replies(2):