Steemit, may not be immediately knocking off major social media platforms down. However, based on what we already see here on Steemit is a thriving community which is growing at a rapid rate. Steemit is still very very young and has alot of optimization and improvements to be made. But I am absolutely certain that what Steemit is accomplishing is the beginning of breaking down all of the points you brought to light. Facebook is looking more and more like an overly large corporate giant who has never financially benefitted it's users directly.

From here, many spin-offs of Steemit can be created based on the Steem token with the same core ideology Steemit holds and slowly but surely bring users over from the giants.

If you are here now, you are a super early adopter and are seeing an extremely early stage of something amazing and revolutionary beginning to emerge!