But by reducing their costs through looser coupling and incremental work. That is where all kind of agile and DevOps research showed.
We do? I seriously doubt that. New good and bad architectures are popping up all the time. And there are plenty of architectures that people totally disagree about, e.g. microservices.
> But by reducing their costs through looser coupling
In my experience loose coupling is something to be generally avoided where possible. It leads to spaghetti systems and unknown data flows. Pretty much the dynamic typing of architecture design.
I'm not exactly sure what point you're trying to make though so I may have misunderstood...