It will be useless if they pay with USDT because basically USTD is using ETH network.
Seriously? You're already 3 years old in this forum and know USDT is only using ETH network? USDT are runned in many network such as algorand, Tron, Omni, Liquid, EOS, and OMG. You will only charged little fee or even zero fees since it's very cheap.
Before start to post, think twicely and post only in a thread/section you know.
Lol it is possible that he didn't know about Tron existence on other blockchain projects, there are some people that are so addicted to ethereum network and tokens only and they believe that every other platforms are bad don't blame the guy