[bkirkby]

"money doesn't grow on trees and runways are very real and scary, so without deadlines companies fundamentally cannot function."

Runways being real doesn't mean you need deadlines. Deadlines are useful to motivate the unmotivated.

The better path to dealing with shrinking runways is early and continuous delivery of valuable software. This is facilitated by making sure the team is aligned and onboard with the solution (for motivation) then giving them the environment, support, and trust to get the job done.

This is further enhanced by self-organized teams since the best architectures, requirements, and designs emerge from self-organizing teams.

With that emergence, the team will deliver valuable and working software at regular intervals (measured by weeks or months at most, preferring the short timescale) and the stakeholders will determine when that valuable software is valuable enough for customers to pay for.

This early and continuous delivery is the primary measure of progress. It also facilitates a welcoming of changes to the requirements at any stage (as the focus is delivering value, not getting a roadmap done).

Roadmaps and deadlines will often get in the way of this system of efficiency in software delivery precisely because the estimation game gives team permission to use all the time negotiated in the estimation, which is already padded enough to ensure an "under promise and over delivery."

All of this is taken straight from the agile manifesto (which is over twenty years old now): https://agilemanifesto.org/principles.html