Ethereum blockchain is best IMHO cause it has largest marketcap as well as still new projects are building up with it. Only because of higher transaction fee, i can't say bsc is better than Ethereum blockchain. Binance Smart Chain just successful to minimize fee, otherwise there are manu things where ethereum is ahead for every matter. Even if bsc get more popular, then fee will also increased. And if binance exchange got hack then bnb might be lost its price badly & bsc might be lost popularity