For me both of them are very trusted. But it's hard to choose one. At this.moment ether is the most popular and most used platform based token. It's one of the most decentralised platform available. In other hand binance was just a exchange based token. But now they have a platform ,they have a dex based on that platform, and Plus they have many usecase of BNB in binance exchange and binance pad. But binance is centralized.
But technically binance chain is better than eth till now. And in terms of coins I think BNB will grow more than eth in term of roi.
Both coins are good, as they remain in the top spots in market cap. BNB has the support of a renowned exchange in the crypto industry (Binance), while ETH is backed by many developers in the decentralized world. One cannot replace the other due to their differences in the way they're designed (either centralized or decentralized). With Ethereum taking the lead in mainstream popularity and market capitalization, it's hard to believe that Binance will beat Ethereum someday. It's like comparing apples vs oranges.
Like it or not, both BNB and ETH will serve their unique purposes in life. Businesses and companies will find BNB useful, while everyday people will find ETH to be a better option for decentralized finance. The latter will always be the winner, because of its first-mover advantage on the crypto/Blockchain industry. With an ample ecosystem of dApps and tokens behind it, no other competitor will be able to stand against ETH on the market. It explains why many people still trust ETH over any other cryptocurrency (besides Bitcoin). Despite ETH being decentralized, it has a slow transaction throughput and high fees. In this sense, BNB is the true winner with its scalability features. It's one of the fastest cryptocurrencies in the world today with very low fees. If you're smart, you'd leverage the benefits from both Blockchain networks in order to obtain peace of mind. With Blockchain interoperability, we can forget about focusing on a single coin's success over the other. It'll be a matter of usability than anything else. As long as BNB or ETH are useful, nothing else matters. Just my opinion