Eos, stellar, tron, steem all these were claimed as ethereum killer...
This ETH killer mentality, we can continue with this counting, then we had Cosmos, BSC, Polkadot and Kusama, still everybody uses ETH
Not many know that even Polkadot was started on ETH and only in Polkadot, Kusama and new blockchains build on Substrate I see as the biggest ETH competitors, why?
Because "Polkadot is a heterogeneous multi-chain interchange and translation architecture which enables customised side-chains to connect with public blockchains. The protocol was created by the Ethereum co-founder Gavin Wood." So he knows for sure what is missing in ETH
.
Additionally, "there are many different use cases for Polkadot parachains, including transaction chains, oracle chains, identity chains, file storage chains, data curation chains, IoT chains, finance chains, and privacy chains. Over 25 projects are building on Polkadot, including Chainlink and Ocean Protocol."
But still as for now Polkadot and Cosmos will not replace Ethereum with currently only 10% of ETH's market capitalization, the project has a correspondingly high potential of course.
Still behind ETH we have the biggest developers community, I think that Vitalik haven't still said his last word here. ETH 2.0 is the answer.
Source used:
https://www.google.com/search?q=polkadot+eth+chain&oq=polkadot+eth+chain&aqs=chrome..69i57.5539j0j1&sourceid=chrome&ie=UTF-8