I don't know about these precise numbers, but ~57% of autistic people have an <85 IQ (cf. 16% in general population), and somewhere between 25% to 50% are nonve

I don't know about these precise numbers, but ~57% of autistic people have an <85 IQ (cf. 16% in general population), and somewhere between 25% to 50% are nonverbal. So 90% may be too high, but it seems very likely that a solid majority has profound difficulties in life. edit: my source is the CDC(https://www.cdc.gov/ncbddd/autism/data.html https://www.cdc.gov/ncbddd/autism/data.html) for IQ and this paper https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3727194/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3727194/ for proportion of nonverbal autism.