I think a more fair view of the term social media should be as a marketing term? When these tech giants were growing they needed a name to refer to them as a whole, but that name reflected what they wanted those services to be viewed as, not the effects they came to have. We see this everywhere in how labelling of things appeal to some of our inner desires -- in this case the need of social interactions -- and not necessarily accurately describing their effects.

I think the main reason these services exist at all is not to create social mediums but to tap into the flows of human communication for profit. And, since their version of communication is, in the true social aspect, an incredibly crippling one compared to the rich, immersive experience of more old ways of interacting -- no wonder we can be left with a deeply dissatisfying feeling when use social media services.