> where were you when the supermarkets did this, literally decades ago?

This is whataboutism.

Many people around here were not old enough to be interested in politics "literally decades ago". And for those who were, the hindsight we have now is a good reason to start getting interested in the issue.

> It's a store, expect the store to take a cut and if you're too successful, compete with you.

The whole point of politics is to fix outstanding issues. "It's always been like that", "suck it" or "fuck you, got mine" rarely make for convincing political speech.