I would treat comments IT folks make on any best practices, especially software development, systems engineering, project management, testing, lean, six sigma etc with massive skepticism. The reason being that IT has never used most best practicalities in these areas.(With some exception for folks who make OS and parts of IBM.)
While Agile has some virtues it is largely a selfish boondoggle IT devs use to do what they want, how they want and for how much they want. It was originally stared becasue IT couldn’t make Agile waterfall work. Since they assumed they used best practices, but did not, they figured the size and complexity must be the issue. So they traded knowing to much up front for ignoring too much. And the punted project or product level cost and scheduile accountability.
The best approach is a hybrid built around what is actually knowable or not knowable up front, proper time, systems engineering and cost adjustments for that, combined with aerospace/DoD type systems engineering, project management and CMMI Level 5 best practices/metrics.