> So do you think if people designed a keyboard from scratch, they would come up with the same traditional layout?
That depends on the constraints. Today's keyboard is a good compromise even today. You can compromise different things, but a full micro-tonal keyboard isn't enough better as to be worth it for most things and once you agree that you must compromise the only question is what. A 9:8 or 10:9 major second are both of rare use and so you probably just agree to get rid of them. The only hard part is 3rds, would you accept how bad they sound in a the current system (in which case a true 5th and a equal tempered 5th are close enough), or try to divide the thirds somehow.
That depends on the constraints. Today's keyboard is a good compromise even today. You can compromise different things, but a full micro-tonal keyboard isn't enough better as to be worth it for most things and once you agree that you must compromise the only question is what. A 9:8 or 10:9 major second are both of rare use and so you probably just agree to get rid of them. The only hard part is 3rds, would you accept how bad they sound in a the current system (in which case a true 5th and a equal tempered 5th are close enough), or try to divide the thirds somehow.