One of the fundamental issues is that upper management sees estimates as bell curves as though 50% of the time a project may finish early. In reality, very few projects on time, let alone early. No one wants to hear about reducing scope but at the same time an MVP that solves the customer problem without feature creep should be evangelized within organizations. In reality, schedule follow more of an exponential function where slippage time goes from bad to worse very quickly as resources/scope/schedule snowball very quickly. Things get scrapped before we see this in practice.