The feedback score is really a qualitative categorization of: legit vs scammer. That's how it's used by most people and how it is expected to be used. There is essentially no quantitative score of how good a vendor's product and service is. If you get low quality product or crappy packaging, you are expected to message the vendor or mention it in your review, but still leave a 5. You're supposed to leave a 1 only if the product never arrived and the vendor is acting shady, or you got an empty package or something that indicates you got scammed.