Well, Steem is our blog for all the people in the world, and most of them we don't know. We can get paid for the posts if we are persistent, patient and do some work on them. Facebook, on the other hand, is more for the friends and people, we do know. That's the main difference. So in my opinion, we can't choose between Steem or Facebook, because each of them has its own purpose.
I agree, we are in a social media/blogging platform interacting with Steem Blockchain that has generated a microeconomic ecosystem and many others interaction aspects.