Please be informed that we are not the ones who are deciding on how much network fee will be charged to the user. All network fees are decided by the miners/validators, and it goes to them directly, not to Trust Wallet.
Regarding Binance, they deduct the network fee from the total amount being withdrawn since they are a centralized exchange. With Trust Wallet, you are interacting directly with the blockchain since you hold the funds and the recovery phrase/private key of the wallet. Each blockchain requires a different type of coin/token for fees. You have to research and understand further how blockchains and non-custodial wallets work.
For further information, please read the following: