The major features of the katana are the blade cross section, which is concave on either side of the cutting edge, and the tempering process that made the core of the blade into strong, resilient steel while the cutting edge remained a more brittle type that could better retain its sharpness.
These two properties, combined, made the blade a good cutting weapon against unarmored opponents.
Meanwhile, at that time, Western swords had largely abandoned cutting and bludgeoning in favor of stabbing. Generally speaking, anyone you really wanted to wound with a sword wore armor--unarmored opponents were typically killed by other types of weapons. And the easiest way to get through armor was ramming a point through a weak spot. When firearms became more cost-effective than swords, the state of the art in blades was simply frozen and romanticized.
Practically anything you can make out of the right modern commodity steels (1060, 5160 spring, 9260 spring) is as good as or better than historically accurate reproductions using era-appropriate manufacturing. If you take the leaf spring (5160 spring) from an old car and re-forge it into a sword, you can do better than a katana. You simply have access to better metal.
And likewise, if you stamp out a few hundred identical pinky-sized stainless steel bits and used wire to make lamellar out of them, you're probably going to be better armored than the best-equipped knight was before the gunpowder age. And shinier.
Like most military technologies, swords were "perfected" only after they became obsolete. As such, the best sword ever made is probably one that was made this year, as a movie prop or display piece, and it will never be used in actual combat. But if you took it back in time to 1000 AD....
These two properties, combined, made the blade a good cutting weapon against unarmored opponents.
Meanwhile, at that time, Western swords had largely abandoned cutting and bludgeoning in favor of stabbing. Generally speaking, anyone you really wanted to wound with a sword wore armor--unarmored opponents were typically killed by other types of weapons. And the easiest way to get through armor was ramming a point through a weak spot. When firearms became more cost-effective than swords, the state of the art in blades was simply frozen and romanticized.
Practically anything you can make out of the right modern commodity steels (1060, 5160 spring, 9260 spring) is as good as or better than historically accurate reproductions using era-appropriate manufacturing. If you take the leaf spring (5160 spring) from an old car and re-forge it into a sword, you can do better than a katana. You simply have access to better metal.
And likewise, if you stamp out a few hundred identical pinky-sized stainless steel bits and used wire to make lamellar out of them, you're probably going to be better armored than the best-equipped knight was before the gunpowder age. And shinier.
Like most military technologies, swords were "perfected" only after they became obsolete. As such, the best sword ever made is probably one that was made this year, as a movie prop or display piece, and it will never be used in actual combat. But if you took it back in time to 1000 AD....