I agree. I've been naive at the beginning of my career, thinking that a great product sells itself, but it's simply not true.

There's so much trash everywhere that is earning millions (book reading apps, silly chart-db software, proprietary SQL databases etc.).

I was quite shocked by the levels of disfunctionality in the software engineering sections of the company I worked at yet still, the company has huge success. We basically got requests from the product team to make something work in a day or two and even though it was completely horrible code that absolutely paralyzes us at some moment in the future, the company still reigns.