Not to disagree with your points, but a brief aside you made me think of:

The fretboard in its current incarnation works well for western music, at the cost of being quite poor at playing for middle-eastern and eastern music.

There have been attempts to address this with microtonal fretboards (which are complicated), but most often they use fretless necks (which are available for guitars and basses).

So, as with all things, the fretboard evolved in a route that favored local optimizations.