Yes, Ethereum is the best after Bitcoin. The popularity is very, very important for a coin to be successful. Ethereum is so popular and this is the main reason to be so good.
Ethereum has more coin supply than bitcoin and ethereum having high liquidity. Compare to bitcoin, ethereum has better technology and it serves more use cases and, benefits a bigger purpose.
No doubt ethereum is a very good technology but it will not replace bitcoin. There are other projects like Polkadot , Caradano or Binance smart chain which are strong cometitors for ethereum.
Also ethereum supply is not fixed but there will be some very good updates in eth 2.0 which will involve coin burn also.