But I remember when USDT-ERC20 first appeared, its withdrawal fee was only 1 $, so I don't know if USDT-TRC20 will increase its fees like that later.
I don't think so, because TRC20 does not use gas like ETH, but maybe there will be changes if there is an update that requires sending USDT on TRC20 network using transaction fees, it is very difficult to make predictions in crypto because the development is so fast.