It operates on Loom sidechain, I think they can handle thousands of tx/second so no issues there. You should look that up. And according to state of dapps, steemit.com has 5k active users in 24 hours, most of them not even gamers so there's really not that much of community to take advantage of here. Of course, of that 5k active users, how may are just passively voting through bid bots, so even a smaller figure is true.
Eth is the #1 smart contract platform in the world and has the highest network effect by far, there's zero reason they would want to move here.
RE: Steem Monsters races past EOS knights on stateofthedapps.com