I've asked about this before and tend to see something like, "It's like that for everyone, no one has an attention span anymore, folks get busy or lose interest."
But I think in some cases, it IS more about oneself--something lacking in communication skill, lack of wit, or whatever. Frankly I think it's about either the deficits of autism, or the result of them (minimal life experience, social avoidance and isolation, leading to a poor grasp of how correspondence works, etc.)
For me, conversations end nearly as soon as they begin. And even if it doesn't, there's "sure, i can continue this on (other platform)'... they reply once there, never again, and next thing is I've been deleted.
I would ask, if you wanted to bring a conversation to another platform but never wanted to use it--why not just decline in the first place or say you don't have the time? Either way is perfectly acceptable. But that's rarely what happens.
I do believe if I wasn't on spectrum these things would be easier, at least. Anyone have some ideas, or how did you fix this problem yourself?