The katana is a solid sword. Couldn't really ask for a better cutter than a curved, two-handed blade.

But I really enjoy debunking the mythos around it.

"The samurai thought the katana had a soul"

Yeah, a lot of them practiced Shinto. Everything had a soul in that religion.

"It's folded a million times, so is superior."

They folded it because that forces out impurities. And Japanese iron had A LOT of impurities. Also, folding a blade too much pushes out the carbon and makes the steel brittle. They folded it only a few times.

"It was lethal on the battlefield."

Kind of. But swords of almost all kinds are garbage against armor. Also, katanas broke all the time (see the impurities in the steel). That's why the samurai often carried two swords, even unarmored. To have a replacement handy.

Yes, the wakizashi is shorter and better indoors, but the tradition started long ago when samurai carried tachi. They'd often have two full on swords at all times. Tachi were seen as disposable.
They beefed up the blades after fighting the Mongols, and created katanas.

Those broke less often, but still often enough to justify carrying a second blade.

"Every blade was created by a master."

Nope. Just like many European blades, most katanas cheaply made to arm troops. Only about 3% of swordsmiths put out quality blades (source, Richard Cohen)