Business was good at first, but when a waiter came, business was suddenly deserted. What's going on here? Is there a saying in Feng Shui that people are not rich?

No way! You should look for the reason from your shop. Maybe business was good before because new customers wanted to buy new things, but after a long time, if the things in the store were unremarkable or the same, customers would not like them very much. Although you can earn as much as you can by opening your own shop, it is also risky. You should keep innovating, put forward some plans and attract customers' attention again. I hope you can tide over the difficulties.