>>935841111quads deserve a late answer
from my understanding, it's a mix of pussyfooting around advertisers as well as some shared psychosis about "The Algorithm (tm)".
The former is definitely a thing, and is not exclusive to youtube.
People seem to agree that the latter reasoning started on tiktok (never been there so idk) due to people perceiving that posts would get "de-prioritized" if they included such language. I wouldn't put it past the CCP to do such a thing, but the idea that they wouldn't just pick up on the word "unalive" instead is hilarious. I also think it's funny how people argue they're bypassing the filters in order to "get the word out" when we all know they really only care about their clout.
Regardless, the trend then spread onto every other normie website. It is very cringe.