Which if you try to do - those agile people will kill you for it.
They wrangle a number out of you which goes into an user story estimate, which feeds into a Gantt chart they use to make their pretty powerpoints they present to upper management to say that the feature will make it into the Q4 release.
If you move this number around the whole estimation will crumble, not that it wont in real life but you deprave them of two things - an illusion of control and somebody to blame when things go south.
You're describing the opposite of Agile Development. The Agile Manifesto says, "Responding to change over following a plan."
> If you move this number around the whole estimation will crumble
I still love this sprint where the further into the sprint we went, the further the ‘remaining work’ line went up.
It’s good we could do that without blame, but it looks super funny.
> Which if you try to do - those agile people will kill you for it.
Does this actually happen to you? This is literally the whole point of agile, is to change the plan as you learn more about your work. If you didn't want to change the plan you'd spend a lot of time on up-front planning and do waterfall.
Like, a Gantt chart is more or less explicitly anti-agile. I'm aware of the 'no true Scotsman' thing but we shouldn't buy into people using agile terms for what is really a BDUF-based plan.