Your question is a little bit unclear. Do you mean potential just in terms of the prices that Ethereum has reached or do you mean in regards to the functions and uses cases that Ethereum is offering? Nowadays there are quite a few other coins or crypto projects out there that are offering an ecosystem with the possibility of smart contracts just like Ethereum does. Examples for that are the Binance with it's smart chain and Solana, but both of those tokens already made x500 or more of their initial price, so i don't know if you still want to invest into those now. Cardano also wants so launch smart contracts soon but it kinda seems they can not get it done.
Another project that wants to create an ecosystem is Radix (XRD). It will still take a year or two until the full functionality is reached but if you invest now then you are still pretty early.