Autistic social anxiety is not "social anxiety" in the typical sense. An anxiety disorder is defined as an "irrational fear". So for example, imagine someone who is afraid to speak in case everyone looks at them and goes "what the heck are you saying you wierdo." If that person is neurotypical, then the chances are that they're very unlikely to get that response. Therefore their fears are irrational, and that is true "social anxiety". If you put an autistic person in that scenario, on the other hand, then probably the reason they're afraid of that response is because they've received it many times before. They're fear is based on repeated past experiences, therefore it is not irrational and not the simply an anxiety disorder. That's why people giving the classic social anxiety responses to autistic people is so unhelpful. "Just go out there and talk to people, it'll be fine," or "keep pushing yourself out of your comfort zone and you'll get more confident," don't work if the problem is real and not just in your head.
This, from what I understand from my own therapist, is why CBT isn't actually great for most neurodivergent folks. It's based on talking down your own anxiety in a rational way and realising that no, people aren't excluding or being mean to you on purpose. If you're on the spectrum, it's very likely that people did in fact purposefully exclude you or were mean based on your personality traits. Therapy based on recognising your own worth, learning some social scripts to help smooth smaller interactions and finding people who do vibe with you is much more valuable. (This take is very much based on my own experience, mind you.)
