But scrum enables you to provide really accurate estimates based on story points. :) /s
... i mean cmon, after all these sprints of *accurately* defined stories and how many points they're worth based on... *wait for it* unknown black box complexities and external parties blocking you or when you work on stuff you have no idea about because it's trial and error. Sure, this story of 1 point took 1 day for this specific task, but it might take a week for another task of 1 story point. But management still want you to use scrum because it works.
You end up saying it will take longer, but apparently it can fit in this sprint until something estimated to take 1 week takes 3 months because you keep opening up a can of worms.