Steemit is just an app...one of many that are already on the platform. There is also busy, chainbb, DTube, Zappl, Steepshot, and there will be a host of others from the SMT program. There are roughly 40K daily active users, so I am not sure how you believe that ship sailed.
As for STEEM itself, there are still 60M on the open market. Plus, as more sign up, the power of the Whales diminishes since their holdings, as a percentage, are reduced. The fact that 75% of the reward pool goes to authors means all new users are taking a piece of that pool. Combined, they are cutting into the Whales percentage.
If memory serves me, the 1% holders dropped from 88% to 81% last year.