The diagnostic criteria would exclude someone from an autism diagnosis unless they had persistent deficits across time and context.

Your example person may function well within a narrow band of capability - the purpose of treatment/support is to expand that band and help maintain it. I'm not advocating forcing support on someone that doesn't want it, but I am for improving someones quality of life by expanding their choice of occupation and social environment.

Without any external support I would wake up, work, sleep, repeat. Eating? Cleaning? annoyances that just interrupt work.

I've made a lot of money doing that but it's unfulfilling and at times, disgusting.

If you want to live in a society that leaves me be - I won't starve to death but I'm never going to have a partner or a family without external services like psychology, occupational therapy, social events.

Whether I pay for these services or someone else does it doesn't matter. I want them to be available for people like me to understand that we are not alone, there's a reason we can only exist comfortably in our narrow slice of the world, and if we want to leave our bubble there is support available.