There is no safest place to stake stablecoins, and it can pay good returns but as far as I know, Binance is a good place, and you can get pretty good returns, especially if you stake a lot of stablecoins there. At least I tried it myself, but I don't stake too many stablecoins, but I use BNB as the main coin to stake.

Also, staking stablecoins on Binance can be a way to increase your number of stablecoins, even if you have to wait a certain amount of time. But before you start, it's better to read the articles on Binance to know more about what to do.