I don't agree with your premise, unless Medium has very recently changed its algorithms. I have been writing here since February and I just went behind the paywall. I had several essays chosen for further distribution before I went behind the paywall, in fact most. I do agree that curation seems to mean very little. I could not tell if there was a significant bump in readership from being chosen. Most of my readers were/are friends of mine, with very few internal readers. I now have a few followers and generate a few internal views, but curation has perhaps brought me tens of views, not hundreds or thousands.