Done is a hard concept. I would honestly like to understand if the 10% is in reality 10% or more like 80%. Is the project done until it has adoption? Until it

Done is a hard concept. I would honestly like to understand if the 10% is in reality 10% or more like 80%. Is the project done until it has adoption? Until it finds utility in someone else's workflow? And does it take 10% more work or 80% more because it's adjacent to what you really are good at?