You miss two of the biggest points of formal diagnosis. Legal rights to accommodation (IEP, workplace) and getting insurance/healthcare money. If an autistic person can’t hold down a job or even live independently only really being diagnosed offically will get them the support they need. I’ve had to ask for accommodation to have noise cancelling headphones in a certain workspace where I was unable to really focus and having my demands backed by legislation and a diagnosis made it much easier to demand that.

On the point of medication though I largely agree, the current system is insanely paternalistic. Like having patients be forced to follow up with doctors about medications they’ve been on for 5 years. However society doesn’t truly want to deal with the true costs of freedom like somebody being able to easily legally acquire a lethal dose of anxiety meds.