Are you implying that 1) everything from the chat is immediately present in the brain when taking up the discussion at a later point, as well as 2) Last time you left the chat, all the the relevant context was well encoded as chat text in the first place?
It's certainly better to have chat text than to not have it, but whether it can make up for the huge cost of asynchronicity is another question (each delay breaks your flow, requiring you to cache-out, cache-in...)
