I think there is a big difference between self-curating the sort of people you want to interact with, and being subjected to algorithmic feed shaping and advertising that surreptitiously pushes only the voices that it thinks you'd be happy hearing.
Or, as it turns out more often, the voices it thinks you'd be most unhappy to hear. Negative emotions are more sticky than positive emotions, and Facebook, et. al., optimize for engagement, not user happiness.
As I put in a different comment, people are naturally going to organize into groups no matter what. You also can't realistically expose yourself to everything (nor would you want to). So there has to be something that decides what you're going to see.
At the end of the day, as faulty as they are, I'd rather have individuals deciding for themselves what they want to see rather than profit-oriented groups that thrive on the misery of their users.
Or, as it turns out more often, the voices it thinks you'd be most unhappy to hear. Negative emotions are more sticky than positive emotions, and Facebook, et. al., optimize for engagement, not user happiness.