It’s the other way around AFAIK. Insurance pays for what’s categorized as a disorder by the DSM. Or did I misunderstand your statement?

And atoms used to be the smallest division of matter. Then we learned about smaller things.

Understanding changes as we do more research into a thing.

No. This is lumping, not splitting

Im not arguing people diagnosed with autism spectrum disorder shouldnt get benefits.

Its that the spectrum isnt as related enough that insividual disorders would make more sense. But that would require getting the health insurance industry to do more adjustments.