The comparison between katanas and European swords in terms of which one is "better" is subjective and depends on various factors, including the specific criteria, combat style, and intended use. Both types of swords have their own unique characteristics and advantages. Here are some considerations:

1. Blade Design and Purpose: Katanas have a curved, single-edged blade designed for versatile cutting, slashing, and thrusting techniques. The curve of the blade allows for efficient cutting motions and can deliver powerful strikes. European swords, on the other hand, can vary in design depending on the specific type, such as longswords, arming swords, or broadswords. European swords often have straight or slightly curved blades and can be optimized for thrusting, cutting, or a combination of both.
2. Combat Style and Tactics: Katanas were traditionally associated with the samurai warriors of feudal Japan and their combat techniques. They emphasize agility, precision, and a combination of cutting and thrusting techniques. European swords were used by knights and warriors throughout various historical periods, and their combat styles varied depending on the time and region. European swordsmanship often focused on a combination of cutting, thrusting, and defensive maneuvers.
3. Historical Context and Cultural Significance: Katanas carry significant cultural and historical importance as the iconic sword of the samurai in feudal Japan. They represent honor, craftsmanship, and the warrior ethos of the samurai class. European swords have their own historical significance in the context of medieval and Renaissance Europe, symbolizing the chivalric traditions of knights and the martial arts of that time.
4. Blade Construction and Techniques: Katanas are typically made using a specific method of Japanese swordsmithing, including the use of different types of steel and the practice of differential hardening to create a sharp cutting edge. European swords were also crafted using various techniques, such as pattern welding, and made with different types of steel based on the available resources and forging traditions.
5. Personal Preference and Context: Determining which sword is "better" depends on personal preference, combat style, and the specific context in which the sword will be used. Factors such as individual skill, training, intended use (e.g., historical reenactment, martial arts, self-defense), and personal aesthetics can all influence the choice between a katana and a European sword.

It's important to note that the notion of one type of sword being universally "better" than another is subjective and depends on specific criteria and preferences. Both katanas and European swords have their own merits, historical contexts, and intended uses. The choice between them depends on factors such as combat style, cultural significance, personal preference, and the specific requirements of the user.