This is such an important one.
Anyone can be 'vulnerable'. Anyone at all. For example, if someone is a patient at a hospital, or in a dentist's chair, they count as 'vulnerable' during that time.
It is not true to say that if someone counts as 'vulnerable', they must be incompetent, a danger, someone who cannot be trusted. Well, not unless we have that view about every single person on the planet.
Vulnerability is about not being able to protect ourselves in particular situations. Some people who have a disability will be vulnerable in some situations. The term for it is often, "An adult who may be vulnerable".
Autism certainly does make us more vulnerable than usual to predators, for example. Not being able to see faces and expressions well is a huge disadvantage. And our social 'clumsiness' is a signal to predators that we could be an easy target.
But that vulnerability is nothing to do with our personal integrity, or our skill set.
I've seen some really appalling thinking from some individuals over the years. The sort of thinking that puts all people like me into the, "...oh that sort of person can't be trusted - they will always need supervising" thing. Or the, "Gosh, I'm alone with Ann - could I be sued for it?" nonsense. Well, it is.
No autistic person ever gained extra safety by ordinary everyday people being afraid of us, afraid of being with us, or denying us humanity and rights. That's not what safeguarding is for. That's not what the term 'vulnerable' means, or should lead to.
Vulnerability means an opportunity to respect an area of possible difficulty for that person.
It may mean a person who could have the most enormous talents and skills to bring to a situation, but who simply cannot see people very well. Or may have difficulty communicating in some situations. And we all do, as humans, don't we. With autism, those difficulties may be specific. That's the difference.
Watching out for predators targeting us? That's handy.
Making sure we are working within our area of skill and training? That's great.
Don't do the, "Gosh, they're all incompetent" thing. It's not true. At all.