I dont think there needs to be competition in this area, similar to how a persons instagram pics can be set to appear on facebook and twitter, it wont take long for these platforms to allow for cross publishing. Akasha is not nearly complete and will almost certainly be delayed, Synereo is also quite a way from Beta, I think Alpha is not even ready. Steem is wayyyy ahead of the game. All 3 are slightly different and you'll probably find that anyone with one of them with have accounts on all 3. choosing 1 to invest in mostly, depending on which suits them. Great blog post by the way!