It sounds like this only applies to decentralized exchanges, eg where exchanges exist on the blockchain and require smart contract execution for trades to take

It sounds like this only applies to decentralized exchanges, eg where exchanges exist on the blockchain and require smart contract execution for trades to take place - ergo this should quite obviously create the opportunity for these front runners to exist and make money. It's confusing because this isn't really specified - it's not possible to do this on Binance or other centralised exchanges as I understand.