It is not that you need a currency it is that there always will be a currency*, just gets made using whatever is available to function as a stand in.That just makes no sense. You always need a currency.
Food for food still works around the world, but commonly is its governmental currency.
If you call it "oppression," then you need to come up with an actual solution.
*even in the hypothetical post scarcity replicators powered by own personal black hole generators or Dyson sphere point you still have the what some would refer to as the Jimi Hendrix Bandana problem (someone comes from earth what was with such an item and now two people want it but otherwise want for nothing), the main solutions that don't involve money** being either teleport cloning (itself its own paradox) or mind control your desires such that you (or indeed one of the members of your society) don't want it (that or push them into VR).
**even at that point merely having mass to feed your black hole or use for your purposes becomes valuable in almost all scenarios so you can't get away from it.