If I'm been true to myself I'll say, there will never be a next Ethereum as all will fail just like they have all failed in the pasts. Ethereum is the reason smart contracts are even a thing in the industry and that's unlikely to die anything soon. No project can replace Ethereum no matter how hard they try. Ethereum makes decentralized easier than any other blockchain excluding bitcoin.

Without Ethernet most of the new trends in the market won't have been possible, the likes of Defi, NFT and decentralized exchanges won't have existed without ethereum founders brainstorming. The fees of the Ethereum blockchain is just the reason we are seeing competitors gaining some momentum, once that is resolved don't think any project not even binance Blockchain can compete again.