Maybe it's all about promotion? The work of an online store now is a very complex process that consists of many sub-processes, and it's hard to identify what exactly affects what if you're not a specialist in this field.
It's really worth talking to specialists. When you don't even suspect what might be wrong with your online store, outsiders can't suggest anything. My experience has shown that I greatly benefited from magento 2 back in stock notification for increasing sales and optimizing communication between me and customers. Maybe it will be useful for you too.
I quite often pay attention to the online stores of my competitors and honestly do not understand in what they are better than mine, although the competitors are more successful. How to find those very features of successful e-commerce business?