there are many blockchains similar to that of eth, the one most similar and with relatively low fees is bsc the only real drawback is that it is not decentralized, the one with the lowest fees ever is matic
Yes, there is a lot of new blockchains available. Matic and BSC are the most useable right now because of low transaction fees and very fast transaction speed. But I don't believe they can able to bet Etehreum blockchain. Ethreum is still the 2nd cryptocurrency and I believe it will stay here in the future also.
As an alternative BSC has given you the option to switch and it turns out that not only BSC, Polygon, Solana also offers the same thing. We just need to choose in which direction the transaction is used. They have made cross-delivery, so it is very good in the future to be able to connect with each other even though they are on different networks.
Solana is also doing well right now, People also talking that it will bet Ehterem soon. I don't believe it, A new coin like Solana cant kill Ethereum's position.