If you take any trade that is supposedly 1:1 you are not bright because there is no reason to do it.

but how do you know that before the swap?

As long as this information balance exists, they are worth equal value

You check the transaction history. So your argument is that they are worth equal as long as the buyer doesn’t have all the information? It’s like claiming that a new CPU is worth the exact same as an old broken one because you can trick someone to buy it for full price if they don’t check it before paying.

good one!

This brings to my mind: Chainalysis or the exchanges Co should offer such service like "bitcoin cleanyness lookup" or similar :-) (maybe some do already and Im not aware of...)

But the thing is: These service work wallet-based.