thank you for your comment. But I think the assumptions are correct. You just need to understand the whole concept of disruptive innovation. As often people pick some parts of it, I also recommend you to read The Innovator’s Manifesto.
you misunderstood the process of traveling upmarket. Traveling upmarket happens after the product/market fit. Before that, companies PIVOT. A quote from the book: “New companies were formed, and markets for the disruptive technologies were found by TRIAL AND ERROR”