I haven't actually investigated it, so I can't give a specific reason.

You can try to find the problems in your restaurant from the following aspects!

The dishes are not good, including raw materials, techniques, cooking skills, updating the menu regularly, retaining the dominant dishes and adding new popular varieties. Let's see if these items have been done.

The service is not good. Think about the whole process from the time the guest enters the door to the time the guest leaves the door. If you don't understand, you can go to a restaurant with good business and compare it.

marketing methods, whether the restaurant has its own unique marketing methods, such as special dishes, special dishes, activities, etc., marketing and publicity programs.

geographical location, whether the location is inconvenient, whether the surrounding environment is not suitable for catering, whether the restaurant positioning is inconsistent with the consumption concept of the surrounding people, and so on.

whether the internal environment of the restaurant is too old, or the hygiene is not good enough, and so on.

The above is for your reference. Without on-the-spot investigation and understanding of the specific business process, it is difficult for anyone to give you an accurate answer. Please analyze it yourself. Although it is important to insist on doing business, we should also be flexible in dealing with the changing market.