I think the presence of BSC is not to compete with Ethereum, but rather to collaborate with Ethereum. So that the Ethereum network will be lighter with the presence of BSC. The concept of BSC and Ethereum concept is almost the same. We can use Ethereum for BSC and BSC for Ethereum. This proves that BSC and Ethereum can collaborate well.
This is a good theory, BSC is created to help the Ethereum network because they are not able to handle the load 
. BSC is a centralized copycat of the ETH network and CZ is trying to copy everything that is available so that he will have a monopoly on the cryptocurrency market and that is his main aim by the way things are going.