Substack and Medium are different platforms that complement each other. They pay in different ways. I still make more money on Medium, but this current version of Boost may mean Substack will earn more for me in the future. It’s slow going, earning the trust of people willing to pay you directly for your work.
But I have had so many high-quality pieces declined for Medium Boosts, and when I move them to Substack, I get subscribers from them. The readers on Substack are a better judge of quality than the Medium curators.