In my opinion it depends on the streamer. Although personally I think they seem chill enough, kai cenat and ishowspeed are exactly what OP is describing. On the other hand there are vtubers, which I'm not sure I would describe as normie-tier although for sure it depends on a lot of factors. Then there are streamers like jerma and northernlion, who definitely have a strong autistic fanbase and probably have a little tism themselves. Overall, I think there's too much variance in livestreaming to lump it all into one category.