it was down to how other people/situations made them feel because they were autistic.
That's a meaningless distinction. The end result is identical.
It would be foolhardy to say that you--an assumed neurotypical person--need to be close, personal friends with everyone in your life. You select your friends--and they select you--based on how well you fit each other. The fundamental problem is that autistic people, broadly speaking, don't fit with neurotypical people. A high-functioning autistic person will eventually realize that, and realize just how utterly alone they are in life. They will realize that the people they think of as friends will never think of them as a friend. Their social circle, if they're lucky, might consist of a small handful of people with overlapping interests, but are not an actual social support network.
I discovered this in 2014 when I failed to complete a suicide, and lost 95% of the people I believed were friends.
I am functional on a surface level. I have a job, I'm mostly self-sufficient, I'm married to someone that is also likely neurodivergent after having been in an abusive relationship for over a decade. I've noticed that the less able we are to mask, the more our social circle contracts. We can not reasonably expect that people will life us, or include us in their social circles.