Comment by goku12

Autism, high functioning or not, rarely comes on its own. It often has comorbidities like PTSD, depression, anxiety disorder and ADHD. Many of these extra disorders, like the former 3 in my list happens due to how autistic people interact with the general society. Bullying, abuse, SA, etc are reported at higher than average rates by autistic people. A diagnosis often helps to deal with them and plan for the future. In addition, medication is used for these conditions. Autism doesn't really have a treatment as far as I know (could use a fact check). There are some therapies available, but they have limited effects.

Another matter is that 'high functioning autism' doesn't mean freedom from hardships. They learn and work differently and don't fit well in regular classrooms. If you search online, you'll find several hilarious accounts of puzzled and perplexed autistic students in their classrooms. Despite being 'high functioning', they really could use accommodations. This is true at home too. If you leave them alone, many would simply starve to death without even ordering food online. Another matter is 'masking' - something high functioning autistic people do in public. It makes them more approachable to others. But it also creates enormous cognitive loads that can later develop into other disorders. Diagnosis really helps in these cases.