This is confirmation bias. I don't think the stereotypes are as generally popular as you claim. My own observational bias is the countless "learn to code", "anyone can code" promotions targeted at youth that make no mention of social limitations.

Depression and anxiety are common in the general population. Social maladaptation is also common, though less so. It is unsurprisingly true that these traits are a bit overrepresented in the tech professions. But tech is not unique in this, the healthcare professions also overrepresent depression, for instance. In either case, it is not even close to a majority.

People that tend to be in these minority groups though by very nature isolate themselves and tend to only see that minority. At worst, online these can lead to some very troublesome echo chambers.