The problems with social media absolutely include the social part and I'd even go as far as saying it's the biggest problem with it.
People post on social media like they're talking privately to their friends...whole lot of opinions they wouldn't dare say within punching distance of a stranger. And because it's to such a broad audience, they will find other people who will share the same awful opinions and feel validated, further entrenching their beliefs. It also encourages exaggerating or outright lying for attention.
Not to take away from the harm of data collection and targeted marketing, of course, but social media has a people problem. And to quote MIB, "A person is smart. People are dumb."