Both Zomato and Box8 are doing things differently because they are different. The question you are asking is a generalization. I do not think such generalization can be made across industries. Just because both are fruits, you can not compare apples and oranges.
If you are looking for a case to case basis feedback then it is a different discussion. Here Zomato, (or Foodpanda, Swiggy) is doing a much better job than Box8. They are locking down the city location and then allowing the user to search for either the food type or the restaurant. This placeholder text helps the user to decide if he wants to use that feature or not.
Conceptually, even Box8 UI is not bad. However, it has failed in implementation. It creates a lot of confusion, increases lot many clicks and in turn results in frustration.
I remember the early days of Zomato when they were in few cities. Those cities were upfront on their site, with the technology available at that time. A user could quickly surmise if the site is helpful to her or not.
Box8 allows me all sort of permutations and combinations. It allows me to enter a city and then informs that Box8 is not available there. It also allows me to jump cities and does not zoom in after entering the first one. There is tremendous confusion about how much granular you are supposed to go. Overall, it is a case of bad implementation.
Coming back to your question, the search is functioning properly, but still the UX is terrible. If they are offering such a widely free entry of location, they should be available at those places.
Long story short, users expect their search to lead them to a meaningful result, which does not happen always in the case of Box8 resulting in a bad user experience.