Not OP, but I’d recommend search engine optimization to find a larger and growing audience - after all Google’s search box is still much more important than Amazon’s and for most people the beginning of product (category) research. Obviously not should optimize by trying to game the system, but simply by creating good, relevant content for your customers. Maybe a blog with extensive, authentic and detailed background information about your product categories and the particular niche you serve. Furthermore a fast, responsive, easy to navigate website - it doesn’t need to be fancy, but frictionless.

Don’t rely on third party platforms for your core business.