Singularity

There are a number of practices and concepts that have been around for a while, have been demonstrated to produce significantly better results where developing a software product is the goal. The ones I am thinking of include:

1. Incremental simultaneous test and code development, aka TDD (both Detroit style and London style).
2. Mob Programming
3. Trunk-based Development

There are more I could list but I suspect these are enough to make the point: by focusing on one thing at a time, everything gets so much simpler. Simpler generally means improved understanding as a result, and better outcomes on several fronts. The solution is focussed on the business problem, is easy to change as-and-when needed, and a long list of other desirable attributes.

It's just really hard to convince people of something they've never experienced.