You still need to manage that change to varying degrees. For every organization which can shift on a whim, there are many more which require mitigation. Normally, there are a lot of things carried forward for internal or external reasons. Developers tend to discount the amount of effort from other actors in the system because they don't understand all of their priorities and which map neatly versus not.

And then you go out of business because you were busy rewriting Netscape Navigator while Microsoft was churning out new versions of Internet Explorer.