Yes, exactly! If you’re “highly functioning”, you’re respectable and seen as human, but you’re also perceived as not having challenges and not deserving accommodations. A lot of times, parents of Autistic kids will shut down Autistic adults for writing about their experiences because hey, if we’re writing, we must be high functioning and so we don’t know what it’s like to have melt-downs, nonverbal periods, etc. But many of us do!
Despite all this, some Autistic people still do use “functioning labels” unironically — for example, IDing as having Asperger’s is sometimes used as a shorthand for “Autistic, but high functioning”. The diagnostic label “Asperger’s” was removed from the manual of mental disorders a few years ago, and the two conditions were combined into “Autism Spectrum Disorder”, to help reflect that the spectrum is complex.