I have one more theory which is that quality has actually improved and therefore is not much of a differentiator. Everyone can get close to (but not really reach) a Stripe level of quality with their apps due to the amazing frontend libraries that are available.<p>The magic saas of today is architecturally harder, like Webflow or Figma, and takes way more engineering. But this is the minority and there are still so many business applications that have not transitioned to the saas model in certain industries.