Each exchange is within a unique currency.
If it’s not, it’s plastic.
As a kid, I was often a greeter at church. Shake hands with everybody.
Each handshake is unique, although of course I formed categories too.
But each hello and handshake was distinct to my relationship with that person, however sparse it is.
Later on I learned about a speed-way when dealing with lots of folks: Always try to know at least a few facts about each person.
But I’d already known about that and did it. It’s also codified as a method to maximize spread while maintaining unique codes for each individual.
In this way, it avoids the generic commodity notion you outline in the OP altogether which, btw, is probably super ineffective.