Any human system where what one person does can affect another is designed. That does not mean it is designed well, intentionally, or holistically but it is, inevitably, designed. So better to try to design well, intentionally, and holistically than to avoid the responsibility.
I’m defining design in human systems as the creation of norms and rules which designate reaction in response to patterns of behavior. In that sense, every human relationship is designed, not by a divine watchmaker but by the system of norms and rules, implicit and explicit, that those relationships are embedded in.
Design is, intentionally, a loaded term in this context. I suspect that something like “evolved” would get less push back. But human systems, to a degree not true of ecological systems (although not altogether false of ecological systems) are systems that are consciously and intentionally manipulated by their agents, resulting in something that I think is deserving of the term design. Humans have the ability to notice the consequences of our choices and in response we can change our own choices and, critically, try to change the choices of others.
An important aside: holistic is not the same as totalizing. Holistic means to look at how the parts interact and try to anticipate and account for the rippling effects of individual design choices. Totalizing means trying to control the way that design choices propagate through a system. Ecologically inspired design thinking is holistic. High modern command and control design thinking is totalizing. Although the words have some similarity in their implication of completeness, they are largely opposites.