But u have USDT ERC20 what makes it better then TRC20?
The answer to this question can be found in the post you quoted. They already explained what makes them not want to support TRON chain.
Now, they have ethereum itself and also three tokens (USDT, DAI and USDC) on ethereum network.
They don't want to support a new chain just for a single token. As they said, there is no TRC20 version of DAI and USDC will be unavailable on Tron network soon. Also, it seems that they are not interested in Tron native token.
I'm not sure that USDT on TRC20 is more popular than ERC20, except for a slightly lower fee, I don't have any special advantages. Even in fees, the difference has not been too big lately.
Currently, the process of necessary adjustment with the MiCA regulation in the EU is underway, and Tether has not yet done anything in this regard, so perhaps it is more important that USDC is listed on eXch.