Wirecutter is excellent although, as you suggest, a restaurant is more subjective, has more dishes, has more variance in both the meals and service, etc. The Wirecutter is also pretty focused on identifying one item (with a couple alternatives) as the best choice. What I actually find they're the best for is when I just want to pick something and don't want to immerse myself in research. I find you won't go far wrong.

That said, better restaurant reviewers do try to explain what they liked or didn't like about a dish. But most people are not better restaurant reviewers, are often basing their opinion on just one visit, and are often writing short reviews that are in a different category from a New York Times reviewer writing an in-depth review after going to the restaurant three times.