Question about liquidity pools

I have a question about the liquidity pools on Binance…. I’ve done a lot of reading and what not about this and sort of have my head wrapped around it but one thing still stumps me….. impermanent loss!!! I’ve read that if one of the assets in a pool fluctuates in price more than the other then there’s a chance of impermanent loss occurring, but how does this work with a pool that uses say USDT? Is USDT not connected directly to the $USD? Say you add liquidity into a pool that uses USDT as one half of the pair, are you not then guaranteed a loss because USDT will never increase in value because of being directly connected to $USD? Say SHIB for example gains 20% in a 24hr period, USDT will never get a 20% gain EVER….. Sorry if it’s a silly question but I don’t see how both pairs in a pool that uses USDT as one half of the pair can increase in value together at the same rate.