A folded steel katana can be good, but the quality and performance of a katana depend on several factors beyond the folding process alone.

Folding steel is a traditional technique used in Japanese swordmaking to purify the steel, remove impurities, and create a more uniform composition. By folding and hammering the steel repeatedly, the swordsmith aims to eliminate voids, even out the carbon content, and improve the blade's overall strength and durability.

However, it's important to note that the folding process is just one aspect of creating a high-quality katana. Other factors that contribute to a katana's quality include the choice of materials, heat treatment, shaping, and the skill and craftsmanship of the swordsmith.

A folded steel katana made by a skilled and experienced swordsmith, using high-quality materials and proper heat treatment, can result in a strong, sharp, and durable blade. The folding process can contribute to the blade's visual appeal and surface texture, as well as its overall strength.

That said, it is also worth noting that modern advancements in steelmaking and heat treatment have led to the production of high-quality swords without the need for extensive folding. Some modern swordsmiths employ alternative techniques and high-grade steels to create exceptional blades.

Ultimately, the quality of a katana is a combination of factors, and while the folding process can be an important aspect, it is not the sole determinant of a katana's quality. The skill and craftsmanship of the swordsmith, along with the choice of materials and other production techniques, all play significant roles in determining the final quality and performance of the katana.