And you, living in your body, must be aware of how hard it is for you to do basically anything.

I get the point you are going for, but this is usually false. Fat people are usually fat their entire life or became so so gradually they didn't recognize the changes until they forgot a lot of how it used to be.

They, like a lot of Leftie adjacent groups, assume their experiences are universal and have trouble imagining a life that isn't their own. To the point where they don't often recognize their obvious issues as being issues, and instead just think its normal human function.

There's an old Tom Segura bit about him having to find out from his wife freaking out that normal people don't have explosive diarrhea every day from their garbage diet. That's how far gone most of these people are from "normal" functioning, and they've "made it work" for so long it doesn't register as that abnormal.