So yet again, someone that is not autistic is telling someone that is autistic that you know better about autism.
That IS paternalism.
I have yet to see a single case of "severe and debilitating disability" caused purely by autism.
The people you are talking about usually have one of many severe debilitating conditions that are not autism in addition to being autistic, and yet people like you go around saying that their problem is they are autistic.
If someone has an intellectual disability AND autism, then the reason they cannot function is because they have an intellectual disability. If someone had an intellectual disability and happened to be black or female, we wouldn't go around saying, "Oh it's because they're a woman", or "it's because they are black"
It's because they're intellectually disabled as well.
When you look at autistic people you need to understand that autistics are like everyone else in their capacity to have other problems that are not autism.
This is compounded by the fact that statistically autistics are more likely to have a co-morbid issue, so people mistaken conflate the symptoms of these co-morbid issues with autism itself. There's probably some good research to be done to find out what it is about autistics that makes the more susceptible or more likely to developed these other conditions that CAN be debilitating.
Thinking that this is autism though is wrong-headed and actually leads to inappropriate treatments being given to autistics, and often to people with other severe problems not being given appropriate assistance because the people around them think it's all about autism.
Intellectual disability is not autism, but can happen in people that are autistic - there's likely an increased incidence as well.
Just because the sample of autistics YOU have met happened to be intellectually disabled, and couldn't function on their own doesn't mean that those traits are the fault of autism, or even common. The vast majority of autistics are NOT intellectually disabled.
Heck the rate of variance in sexual orientation and gender identity is more than four times higher in autistics, why aren't we blaming autism for people being gay now too?
This is the same fallacy that leads someone that met a couple black people that happened to be criminals to conclude that all black people are criminals. We'd readily identify that fallacy as both wrong headed, and racist.
So please recognise that the way you are viewing autism is exactly like that.
It's wrong. Trying to dismiss my opinion (as an autistic, that other than intellect could be considered fairly 'severe' on the spectrum) by saying I have not met people with 'severe' autism says several things that you can't reasonably claim.
1. That I have not met people with what YOU call 'severe autism'. I have met many, probably many more than you as an autistic self-advocate.
2. That you are making an assumption about my functionality purely on the basis that I am capable of talking for myself. Facilitated communication has been proving that non-verbal autistics can communicate perfectly well with non-verbal tools. Such as by typing!
3. That you as a non-autistic know more about autism that I do, as an autistic.
I couldn't find a more textbook example of inappropriate paternalism if I tried.
Paternalism (or parentalism) is behavior, by a person, organization or state, which limits some person or group's liberty or autonomy for their own good. Paternalism can also imply that the behavior is against or regardless of the will of a person, or also that the behavior expresses an attitude of superiority.
When autistic adults are saying this attitude and view of autism is harmful to autistics and you need to find excuses to dismiss our views, that's what is disgusting.