As a frequent user in Albuquerque, my personal experience with GrubHub search is that it returns very strange results, and categorizations are unreliable. For example a restaurant whose name contains my query (for a query like "Chinese" or "Thai") may not even appear in the results for that query, and relevant results will be buried beneath completely irrelevant results (like a taco place and an ice cream joint might appear above a Thai restaurant in the above example).

Further restaurants will be miscategorized or eg have the word "sushi" in the name, and yet not appear in the sushi category (not sure if there's actually a sushi category in the app, just using that as an example).