Though I also agree with the other person who said that average stars don't make sense for coffee because different people like different flavors. An average of stars only works if it's given that people want the same "best" flavor profile of "best coffee taste", and that's very obviously not true. People don't share taste buds or desires in common. All ratings of subjective experiences have the same problem. Monolithic wine ratings are likewise useless for the same reason.
If one person loves acidity and hates bitterness, and another person loves bitterness and hates acidity, that doesn't make bitter coffee and acid coffee both mid. It makes them both great for one person and not the other. Failing to capture that fails to help people find something they'll like.