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.
That doesn’t really work as an argument when slow is also used as a euphemism for people with mental disabilities. Saying “it literally means slow, I’m calling them slow” just makes it sound like you’re still being ableist. I don’t believe calling someone slow as an insult is ableist, I’m only saying that the train of thought feels goofy. Like, “oh? You weren’t trying to use the slur usage of the word and were using the technical usage? The technical usage that means slow? Another word people use as an insult and a euphemism for the exact same kinds of people and scenarios as the other one?”