I think it'd be reasonable to say that if humans didn't have eyes (and didn't have any other sensory enhancements beyond what sighted humans have today), and then a new human was born with eyes, that new human would be strictly "better off" than the old humans without eyes. Certainly the new human wouldn't say the old humans were "disabled", but at the very least, the new human would not have trouble communicating with the old humans, or doing anything that the old humans could do.
But if everyone were autistic (as we define it today), and then someone was born that we would consider "neurotypical" (in this world, of course, they would be neurodivergent!), then that "non-autistic" person would probably be at a huge disadvantage (socially) in that society, so it'd be reasonable to call that person "disabled", even though we'd consider that person typical.
So yes, "disabled" is just a term we use to describe people in the minority, who have some sort of condition (physical or mental) that could confer a disadvantage upon them in our current society.
So to your statement:
> I too, thought the idea that “autistic people are disabled because neurotypical people considers autism is a disability” was not very convincing.
I've never really thought about it that way. My understanding would be more like "autistic people are disabled because their condition puts them at a disadvantage when interacting with the neurotypical world". And I think that jives with how we should think about disability: it's something that makes it harder for someone to interact (physically, socially, etc.) with the world as it is. We may try to make the world easier on disabled people -- ramps for those who cannot walk, audible signals for those who cannot see, attempts to change how we communicate with those who are neurodivergent -- but at the end of the day those people still have a disability, as there will always be parts of the world that they'll be unable to navigate the way a "non-disabled" person could.