Just in case I have bnb and eth, and for those who dont know what to do, I suggest investing in both. About the future, I dont think that bnb can overtake ethereum, some people like decentralized ethereum and Vitalik, on other side CZ and bnb are new on the market, and lets not get carried away with their quick success, time needs to pass for them to establish what ethereum already have.
It is possible for Bitcoin to supersede ethereum if they dont also work to improve their chain services, major thing I have been hearing people seek for in Ethereum, is the speed and security, this is one complain that I feel Bitcoin too advantage on to better their own system by providing solution to it which many people have seen.
Once people starts getting use to the BNB chain speed and reviews comes out on different media, gradually, people will start shifting their attention to migrating to BNB chain for the existing ones, while the new ones will basically develop their project using BNB chain.