No, "user" is a great word if you're talking about what it's like to use the product, and how to improve the experience of using it. A word like "buyer" or "seller" might be better in some cases, but risk being to narrow, because a seller for instance will occasionally have other goals in the app then just doing a sale.

Similarly, "user" is probably not a great word when you're talking about business, because your customers do more than just use the app.

I don't mind being both a user and a customer and an individual, depending on who's talking about me in what context.