Got a little bit off-topic here.
In any case, it comes down to this: there are a lot of people who don’t understand that social media is, first and foremost, a marketing venue… and most people suck at marketing. And I’m not talking about ads. When a person posts photos of their vacation or their car or their cat, they’re publicizing those facets of their lives… illustrating how good they have it. When a person posts their political opinions, they’re engaging in propaganda. When they post their art, they’re marketing their skills in that particular medium. And so on.
The problem is that quite a few people (most?) don’t understand that they’re engaging in marketing of some sort when they’re on social media and therefore they fail to treat it as such… and then of the people who do know that they’re marketing, quite a few (most?) do it poorly and annoyingly.
Granted, there are a few corners of each social media platform where people can engage in real socializing, but they’re pockets and corners… and most of them are based on communities that started outside of the platform.