you mean polkadot will completely replace ethereum? I think not even though Polkadot will develop further still eth will be known as the first smart contract maker and if polkadot is monitored 100 $ maybe eth will be at 5000 $ later.
That might be the actual scenario to happened after that certain point in terms of value, Polkadot is gaining but also Eth doing the same and with lots of supporters and investors who continue to value this coin, it's still far from being replaced as the 2nd top project inside this market,.
In a simple reply, I did say No, polkadot is never going to kill eth for whatever reason or reasons, but I do believe that the project will do well even more than its currently doing, but when it coming to killing eth, it is just some kind of a joke, and just like some posters already said, polkadot posses absolutely no threat to ether, eth will be here for a very very long time.
Indeed, the good thing is to catch out the pump and enjoy the benefits, instead of thinking of it as a replacement of ETH success
treat it as investment asset then enjoy the benefits.