Demo-driven development is a great forcing function and it can work.

Also when you demo something to the management/stakeholders, you communicate progress, and even can get some additional funding/budget/time.

When you demoing for yourself/team, you can get more confidence in yourself and some dopamine.

This can be relevant:

My approach to building large technical projects (mitchellh.com)

https://news.ycombinator.com/item?id=36161397