I'm a fan of Substack - but it looks like they might be hitting some issues as they rush to attract famous writers to the platform - and paying them. On the outside it looks good that famous writers use you - but if you are paying them - and not discllosing that - we have an issue.
Beyond that, to pay someone means that you are choosing not to pay someone else - at which point you are becoming a publisher - not a platform and thus arguably support/agree with those writers words and opinions. What then distinguished you from any other publishing vehicle.
Then again there is this (spolier alert - an opposite pov : Adding My Data Point To The Discussion Of Substack Advances.