As we speak there are actually a few who could be a competitor to ETH . Neo( even though I like them) I feel they will always play second fiddle to ETH even though you can use more than one programming languages. Ada will be competitive but their method offers a slower development time in all things( not a bad thing). Zil their sharding tech is almost ready, it’ll be ETH with a stable high speed network with out the bottle necking the ETH sufferers from