Of course, because polygon's gas fees are far lower than BSC's, this may happen; it's only that BSC is still more popular than polygon at the moment, thus many new projects are still using BSC smart contracts. The Proof-of-Stake (PoS) consensus process is used by Polygon, while Proof-of-Stake-Authority (PoSA) is used by BSC. Validators are picked for the PoS consensus method depending on how dedicated a member in the community is to the network; the larger the stake, the higher the possibility of being chosen as a validator.