While often confused with socially extroverted and socially introverted, the Meyer Briggs is made for determining the primary modes in which people interpret the world: with social values or internal understanding and by branching out from big ideas or by condensing concepts into conclusions.
When it comes to socially extroverted/introverted people, there's a lot of judgement towards one end of the scale or the other(while ignoring the idea of ambiverts)... When social anxiety disorders simple manifest in many different ways.
Socially successful extroverts who have plenty of connections, and are fine with company but are codependent and require it to function, floundering without.
Socially inept extroverts who desire constant company but have no connections and lie to themselves about being okay with being alone.
Socially successful introverts who are constantly burnt way out over their obligations, which they may dispise.
Socially inept introverts who may be self assured with their own view of their levels of interaction, but fail completely at participating in society to their own unaware detriment.
That's just based on 2 basic axis. All that and more exists. Literally anything at an extreme is a disorder if it impedes your ability to function. People do talk about these issues. Just not as often as they get conflated together or simplified into unusability.
It's complicated, and while annoying, simplifying concepts down to stereotypes is the level at which most dialogue happens. Lots of cases are miscategorized and dismissed due to the lack of vocabulary. But at least there is dialogue. It may take time and effort, but expanding the caricatures of manga characters to real life situations is progress.