From fully asynchronous work to fully synchronous work, there is actually a spectrum of possible working styles.
When we're collaborating with others, there's a natural human tendency to desire some privacy while working through something, the freedom to take a piece of the creative work and play out different ideas, move things around, edit and refactor, without fear of judgement or the burden of having to explain or communicate our thinking or concern for overhauling sections where another is actively reading or working.
For example, when people are working on a shared Notion or Google Doc they frequently create a copy of the doc in a private / offline space and make larger changes, overhaul specific sections, flesh out their wild ideas. This semi-private exploration is vital to the creative process.
And yet, in "fully synchronous" docs where every change is instantly shared, this kind of private exploration isn't possible. This makes editors more conservative and creates friction in the creative process.
Potential ways of enabling this flow: