I would argue that leaving socially awkward naturally reticent and off-putting male children, ie your standard internet autist, alone in his room (like he wants) from childhood forward is horrifically damaging. There is a subset of the socially awkward that can never assimilate in any way, I’m sure, but the vastly larger portion can, at least in some ways. They can learn to shower. They can learn how to not be such a complete retard that the other boys feel compelled to beat the shit out of them, they can learn how to not creep girls out, etc. Maybe not all these accomplishments are within reach for every autist, but every little bit of training in how to conform helps.
What doesn’t help are parents who enable his absorption into the disembodied fantasy world that is the internet. He needs more meatspace interaction, not less. But you get parents who are either so entirely indulgent that they facilitate his isolation or just so plain annoyed by and possibly afraid of him that it‘s easier to just let him stay isolated.
The most extreme cases of this are always tragic, like Adam Lanza, who had the most toxic blend possible. He’s exactly the sort who follows a special interest into a nightmare. His was just school shootings instead of troonery.
Your weirdo son needs to leave the goddamn house. And he needs to not develop the sense that he is an all powerful God who can control the entire household (which since you let him never leave is The Whole World) the same way he can control his internet fantasy life. Sure, your weirdo may get in huge trouble for stalking girls from around town. Isn’t that better than having him stalking his mother or sister? It is, yes, it is.