It seems to me that Steem has solved the trilemma with Hivemind & MIRA.
Nodes can now be run on commodity hardware thus there can be full decentralisation.
Steem has proven its high transaction throughput and security over a long period.
Steem Engine and other side chains are providing second layer protocols for many other applications.
I don't really see what advantage Harmony has over Steem.
As much as I like STEEM, the platform cannot natively handle smart contracts.
Steem Engine intends to solve that, but we don't have any major live executions on it to prove its functionality. The Trilemma proposed by Vitalik was referring to smart contract networks; STEEM is not a part of that list, at least not yet.
In fact, even the betting applications built on STEEM don't utilize smart contracts to deliver trustless interactions. Betting applications are the lowest hanging fruit for pretty much every smart contract network.