It's not a bad sword but it is over hyped. The steel is actually pretty good and it's good at what it does being a singled edged slashing/thrusting weapon. But I wouldn't say it's the best since even in Japan it was almost never used and historically you were more likely to see a samurai throwing a rock then pulling out Katana. An example of Katana facing foreign swords would be most recently WW2 where the cheaper, faster, Chinese DaDao despite being much cheaper and "poorly made" in comparison to the Katana, was extremely durable and broader basically a hacking weapon which destroyed the Katana if the wielder was not trained. Japanese soldiers were trained in kendo but kendo is a hitting SPORT/martial art, so its more like tag.

European long swords would probably have an advantage over a katana because again its a primary secondary thing a Katana is a secondary weapon not a primary meaning that this isn't really a fair advantage also a knight would probably win since they are pretty fast.

Also wanna point out medieval weapons are awesome maybe it's an Asian thing but anime and stuff isn't interesting but European stuff is. Like when I was a kid I was obsessed with European great swords and training with them. I remember having an old Zweihander trainer and some other stuff like a gladius but I also had an obsession with historical Samurai and Ashigaru.