BitShares and Steemit are both highly centralized. Their architecture is very similar to a traditional server client set up: they have a small number of trusted nodes, and non validating clients that depend on them.

And the transactions in Steemit at least are generally very low value, with 1-cent upvotes and article/comment entries making up the bulk of them. In comparison, the average value of an Ethereum transaction is $10,000.