Agile is a great methodology for teams that would work pretty well using any methodology but unfortunately that is not true for most teams. It requires a product owner who has an understanding of the problem being solved at both the big picture and middle levels and then programmers who understand it at the big picture and lowest levels. Waterfall was designed to make sure that even in large dysfunctional organizations where the individuals lack that understanding it could be effectively communicated in some form through out the product/feature development workflow by way of “process”. Just removing the process isn’t going to work if the underlying problems that necessitated it still remain. That’s the real reason Agile isn’t working.