We spend a lot of time asking why things don't work, but we rarely ask why things work.

It's interesting to consider that the most powerful, actionable parts of agile, Kanban, Scrum, and DevOps are just classic lean under the hood.

"Agile methods were developed by assembling the best practices from successful projects. While the combinations of best practices found in agile methods exhibit the core values and principles of a lean approach, it can be difficult to understand the reasons why agile processes work just from examining their practices…​

Mapping agile practices to lean concepts such as value, flow, pull and waste can help explain why agile works, and offer new insights to guide process improvements."
— Paul Hodgetts, Lean is More