The WTO which presently rules the economic aspects of the world with countries increasingly only ruling the political. (Thats why things ae so confusing here in the US) insists its human rights agnostic, That ensures that countries cant limit trade to the most evil countries, based on human rights. They all have to be treated equally.
If a country enacts a rule that did something like that the WTO could sanction them if the evil country brought suit, because the suit could only be decided on “facts” the principle one being that the other country was discriminating against them for a reason which was not in the WTO rules. And they would win.
Exceptions are so narrow as to almost never be supportable. This makes it so all the gains earned by workers in the 20th century almost without exception are all on a death watch as these trade rules roll them back one by one.