Choosing the less social network?

Where lies the benefit of the social network?

Is it in it's stated goals and aims? 

I think not. At least not for you and I in general terms. A social networking platform may have lofty and altruistic goals but we do not derive any value from selecting them on this basis, or certainly not on the strength of this merit alone.

Is it in the impressive list of features?

No, not really. Beyond a simple method to broadcast communication to your peers few other features are essential to the operation of any given social network. Twitter has proven this, starting with the ability to opt-in to one and others 140 character broadcasts. It's defining feature. Embedded video and image hosting, even baked in support for hash tags and at-replies came later.

A means for discussion is the only essential feature.

So where is the benefit?

The real benefit of a social network is you and I. The same resource that they do or don't sell to their advertiser customers is the same benefit that we ourselves derive. If a social network isn't used by the people you want to connect with, then the social aspect does not work for you. If you remove this element, then the two above however impressive are meaningless. Go where the people you want to interact with are found.