The quality of a card isn't absolute, it's personalized to the learner. There are ways to make an almost universally bad card (e.g. putting way too much information or a misleading image), but a really "good" card comes from the learner engaging with the material first before making the card.

The program doesn't know what's in the learner's head and what associations the learner will make. That's the benefit of making your own card.