1) Subscription is not the same thing as micropayments (as they are commonly understood)

2) It's pretty unclear to me that Substack actually lets "legions" of writers make a living. https://substack.com/discover lists the top (income making?) writers, and it drops off very quickly. By number 25, it is "hundreds of subscribers" paying $10/month. That's a nice hobby income but isn't really "a living".