Were katanas really that great?

I understand that the process to make them was amazing, and they are a marvel to behold, but was the object itself as good as they say? They are often admired for their sharpness, but katana swords really that much sharper than European and other Asian (Arabian and Indian) swords? Were they made of better steel?
 

It’s not really a matter of sharpness. Shadiversity covered this topic well. The way that a katana and a European arming sword and longsword are different is literally just based on the way that they are used. When people look at a katana or wakizashi, they should also look more into the martial art taught on how they are used. The same goes with a European blade like the rapier and estoc’s stylish stance rather than just the weapon. Sharpness is also a futile topic because the smith determines that factor, not the way the blade is shaped. Just some internet knowledge you know.