Polkadot offers better scalability than the ethereum blockchain. It offers relay chain, cross-blockchain features, forkless network, decentralized governance and all these are not available in the ethereum network. Actually, Polkadot offers all the solutions to those problems that the ethereum network can not. So many projects are using the Polkadot network. Do you think Polkadot is really Ethreum killer?
in the past i predict if waves and lisk could be the next ethereum but thats only my dream
and now you predict if polkadot will take the place of ethereum as the best altcoins, maybe thats could be your dream my friend
because its impossible to replace ethereum as the best alts for now