Product management is one reason but not the most important one. The problem with startups is timing. Look at the S curve. Before mass adaption, most customers

Product management is one reason but not the most important one. The problem with startups is timing. Look at the S curve. Before mass adaption, most customers will say that they have no need for the product and the market will look small and not valuable When the steep rise on the S curve starts, suddenly all of prev customers wants the product, and all of the startup that are READY at this point, will suddenly found "product market fit". However, to be ready for the mass adoption, you need to start two years in advance, where the market looks small and not interesting. And when doing product management will tell you that there is no market. The capital issue occur when the start of mass adaption takes too long (e.g. VR, Bitcoin). I.e. the startup is ready for the mass adaption but the market fail to pick up. So there is a capital issue.