Ironically, this post comes off as out of touch. The purpose of the various martial arts isn't just to win in a life-or-death brawl or murder people as efficiently as possible. Similarly, the point of programming isn't just to generate as much code as possible, or only to be more "productive".
In Musashi's era, meaning the late 1500s, kendo (sword fighting) was absolutely about being as "productive" (read: lethal) as possible.
As it happens, Musashi lived through the era when firearms were introduced to Japan, and participated in the decisive Battle of Sekigahara (1600) where both sides used them extensively.
The end of the Sengoku Jidai was triggered by a warlord (Nobunaga) who equipped his armies with massed ashigaru levies armed with long spears and tanegashima arquebuses. It was absolutely a technological brawl where the valiant highly trained cavalry of warlord's like Takeda Shingen got mowed down by the bullets of musketeers stationed behind well prepared and covered firing positions.
If it was still going on today, the warlords would be adopting drone warfare and vibecoded 3d printed cruise missiles.