If this is the case, I don’t understand why Patreon and other sites cannot adopt the same approach. Very easy to remove buy buttons in apps, and redirect users to patreon.com to manage subscriptions for content creators and “per content” payments.

iOS and Google apps just used to view content.

Patreon is a relatively small company so velocity to complete this effort even amongst multiple teams should be at most a few weeks. If this was a Fortune 500, I would probably estimate it at 2-3 months.