There’s a clear campaign against the mentally ill with the global rise of fascism. Lots of it shows up in anti homeless rhetoric, but you can see it in the MAHA and anti vaccination movements.
There’s no reason to use the word “r-tarded” to describe someone. As someone who’s worked with the intellectually challenged, it’s an insult to them to compare them with people who are willfully ignorant.
Myself and many of my friends were called it a lot growing up, but we still said it to and about each other super often. Now I kinda think people should probably avoid it, but I don’t think it’s “disgusting” for people to think they can say it, it’s very normalized and most people see it as a synonym for “you should know better than this” or “that is the dumbest thing ever.” I’ve seen it used 500x more in those ways than actually against anyone (not saying it’s rare people are called that, just extremely common to see it used not against anyone)