My opinion is that Agile is intended to be vague, as there can't be a silver bullet plan that fits every occasion. Of course, "no silver bullet" sells way worse

My opinion is that Agile is intended to be vague, as there can't be a silver bullet plan that fits every occasion. Of course, "no silver bullet" sells way worse than "I've got a silver bullet for you right here, Mr. CEO, just sign here". Let's check some "principles" posted at https://agilemanifesto.org/principles.html https://agilemanifesto.org/principles.html Our highest priority is to satisfy the customer through early and continuous delivery of valuable software. Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage. Deliver working software frequently, from a couple of weeks to a couple of months, with a preference to the shorter timescale. Business people and developers must work together daily throughout the project. To me it looks like all of the above is screaming at you "quit your great perfect plan and look at the real world instead". If something's wrong, adapt and adjust - this is what agility is about. You can't calcify agility. P.S. not really in any particular argument with you, just that your comment prompted me to write some thoughts that have coagulated in my mind while going through the comments here.