I think Ethereum does have a good development but if the price of Ethereum rivals Bitcoin, in my opinion, it is not possible.
Bitcoin has more advantages than Ethereum.
Ethereum cannot experience the bubble, so the movement of the price increase is quite slow and Ethereum price is very stable.
Rival is not should be passing the price but at least stand behind bitcoin. This great development make supporters always support etherium as their first choice before support other coin. Etherium aslo acceptable coin since its pairs to other altcoin and also etherium make its smart contract very valuable.