When it comes to who will replace Ethereum, the answer is not so simple. While there are a few contenders in the race to be the top smart contract platform, there is no clear winner at this time.
Ethereum has been the leading smart contract platform for a few years now, but it is facing stiff competition from newer platforms like EOS and Cardano. These newer platforms offer faster transaction speeds and more scalability than Ethereum, which could make them more attractive to developers in the future.
At this time, it is still too early to say who will replace Ethereum as the top smart contract platform. However, if one of the newer platforms can offer a better user experience and attract more developers, then it is possible that they could eventually overtake Ethereum.