Is using a copyrighted image/image that isn't yours as an avatar actually okay?

Was thinking of adding an avatar (random image I like off a search) and got to wondering this.

I think it's fine if you're not claiming it is yours. And most people assume that any generic/immediately recognizable avatar is just an image off the internet that the user just likes.

Though there's maybe a weird grey area where if you use artwork from someone that isn't like... a super established artist (hard line to draw) it's kind of iffy. I wouldn't feel right using someone's drawing off Instagram. But plenty of people use anime avatars from manga etc. and I don't see an issue.

Not the most important topic in the world but I thought it was fun to think about.