Autism documentaries

This wasn’t ‘an autism documentary’, it was a documentary about someone who is autistic, some of the things they struggle with, and how they now able to use their status to try and bring awareness to others.

I doubt a single documentary could cover it.  A series might.  There are a number of them being produced now, which is good.  You are right though, they are covering diagnoses in adulthood, but later adulthood is different again and has it's own complexities.  It would be worthy of an episode on its own.

They could make a series

The answer is in the question! How could anyone cover all the complexities in a one hour show? It couldn't even be done in a ten hour series. Then the fact it is being made primarily for NTs so has to include stuff to make it appealing to them. At least they are making a start!