[Twisol]

I don't think that term has been appropriate for a long time... Wikipedia seems to indicate similarly.

https://en.m.wikipedia.org/wiki/Mongolian_idiocy

I saw someone on Rocket League use that term as an insult. When I said it was a slur, they said it just meant "stupid", heh. No, buddy... there's a lot more to it than that.

[IshKebab]

There was a lot more to it than that. Insults tend to gradually lose their meaning until they just become synonyms for "stupid". E.g. "idiot", "dumb", "gay".