A startup must be in the business of disruptive innovation. Making a company that is only slightly better than the incumbent is a path to failure. In Eager Seller, Stony Buyers John Guernville describes the 9x problem.
In order to get users to change to a new solution, it must be 9 times better than how they solve the problem already. That means sustaining innovation — making a product better — is not sufficient to build a new business. It must be so radically different that users are willing to take on the pain and annoyance of changing products to get the new benefits
C Wodtke: Needfinding for disruptive innovation