If you refuse to buy after it hits steam, then you’re just 1 of several billion who didn’t buy the game.
No, you have it backwards. If people buy the game when it goes on Steam, that tells the developer they can double dip buy going Epic exclusive then releasing at full price on Steam a year later with no repurcussions.
The only way to make the publisher learn to not go Epic exclusive is to not buy those games at all, even after they are brought onto other marketplaces
You could always sail the high seas