The essence of the difference between keyboard and mouse interfaces is simply that the mouse introduces that extra mechanical layer between user’s intent and in

The essence of the difference between keyboard and mouse interfaces is simply that the mouse introduces that extra mechanical layer between user’s intent and internal APIs, but offers the advantage of discoverability. That advantage and disadvantage tradeoff heavily depends on the nature of core functionality, how it’s mapped to the UI by the developer/designer, and user’s overall experience and familiarity with software.