BSCs are faster, cheaper, and they are more centralized than ETH. If you are someone who likes fast and cheap, then BSC is the perfect choice. But if you are a person who likes safety and values privacy, then ETH is a much more perfect choice.

If you want to be profitable, you should invest in both because both are topcoins that are considered safe, the price potential of both is still likely to increase many times in the future so  you hold both, you will get huge profits.