Most people are diagnosed with autism or ADHD because they have problems due to trauma, or they have problems which gave them trauma, or them having these problems made them more sensitive, which in turn traumatised them when it wouldn't have done the same to others. Many of the diagnostic criteria are trauma responses or otherwise external signals which have very little to do with the internal experience of actually having autism or ADHD.
What does a well-developed, untraumatised person with autism or ADHD even look like? We can make some broad statements based on assumptions, but many of those people won't even be diagnosed, since they've never had reason to. What made life work out for them isn't an active area of study, since finding that group of people is close to impossible.