You are missing something. Multiple things actually.
most content isn’t uploaded by the copyright holder (e.g. TV excerpts)
demonetized videos will still have ads (at least for people without ad blockers)
videos are used for machine learning without credit to authors or financial compensation (especially without consent when it’s not the copyright holder uploading them)
It’s a “product” that profits billions off other people’s - often stolen - works.
YouTube steals other people’s work?
I tend to watch content creators who willingly put their content on YouTube. Am I missing something here…?
You are missing something. Multiple things actually.