Polygon and Binance (along with some other entities), are trying to answer the high gas fees on the Ethereum main network, by setting up their own proprietary networks, running on the Ethereum protocol - with few modifications to match the scope of each network. In essence, these are simply test (often centralized) networks, running independently from the main network. This is why any transaction taking place within those networks is not - and cannot - be part of the main network ledger. Similarly, any smart contracts deployed on those networks, are valid only there.

What happens when you transfer your tokens from the Ethereum main net to those other networks, is up to each network operator to decide. Polygon, for instance, has set up 'bridge accounts' (it's the same method all centralized exchanges are using), that are used to hold any assets transferred to and from their network to the Ethereum main-net, when you are depositing or withdrawing assets. Binance is not following that path themselves. Rather, they are trying to make you keep your assets within their network, by inventing any possible way to achieve that (and pocketing any difference in the form of fees or penalties imposed to your account, including their own 'monetary' unit that is used for transaction fees).

Any asset deployed in Binance network, will never be deployed on the Ethereum main net, unless Binance allows its developers to do so - and they have every reason not to.