An issue with long-form and asynchronous discourse is wasted motion. Without shared assumptions, the logic and info that locutor 1 adduces is less relevant to locutor 2 than to locutor 1. And, that effect becomes more pronounced as locutor 1 goes down a path of reasoning, constructing more context that locutor 2 doesn't share. (OTOH, long-form is better in terms of individual thinking.)