I'm not sure I follow.
The challenge with this formulation of "ever-changing" is that it assumes that things like Agile methods are somehow creating the capacity to iterate toward something of value with intention and ambition in such a way that you'll achieve whatever it is that you're trying to achieve.
However, what happens is that the lack of rigor in software development today seems to cause the lineage of development and associated created technology to drift further and further away from the desired commercial goal as those goals change or mutate.
Creating a bunch of brittle technology and technical debt to poorly approximate Purpose-A (a purpose by the way that you might be able to formally prove trivially is actually impossible and you either shouldn't waste the money or should intentionally select the best sub-optimal solution) doesn't help you get to Purpose-B any faster. As you become aware that Purpose-B is a thing you need to angle toward, you're still dealing with the pile of bubblegum, toothpicks, and instruction manuals written in alien script that still hasn't achieved Purpose-A.
It's a really weird thing to me that as an entire ecosystem and community we've decided that the most valuable way to approach software is to declare that it's impossible to ever "finish" it.
If I have a series of high-assurance layers to build upon that I know I can trust, then iterating and adapting to changes actually becomes faster and easier, because I know the surface area of where a problem can actually reside and how deep in any part of a system I actually have to uproot and start over. In the current formulation of the world, basically everything is a suspect, and basically any solution is considered viable... whether it truly is or not.
I've been in situations where Product Managers and Engineers spent months off and on arguing over some proposed solution or feature and never getting anywhere because everybody's basis was built on social capital, political capital, and mythology. What finally killed the conversation and allowed progress to actually happen? When a TLA+ model that invalidated one of the proposed hypotheses was presented. "Well, look. The way you want to do this is actually impossible. It will need to be done like this, this, or this instead." Seven... _seven_... sprints of about a dozen people wasted because nobody could formalize either the requirement or the approach. Until somebody did. This wasn't for a safety-critical system either.