I read your initial link; I think the issue is that their RCT work was innovative within the development subtopic in economics, which had ordinarily been dominated by observational studies. So the Nobel is for the RCT work in the context of policy making, not the modeling of optimal experimental design, which you correctly point out goes back a very long time.
My interest in this topic is more foundational. Given my field will not be able to produce a credible RCT for various interventions and populations, what studies should a skeptic accept as evidence? When can proponents of an intervention argue that insistence on RCT is unjustified in a particular context?
I’m guided by this quote from the introduction to Paul Rosenbaum’s text Observational Studies
Blockquote
Scientific evidence is commonly and properly greeted with objections, skepticism, and doubt. Some objections come from those who simply do not like the conclusions, but setting aside such unscientific reactions, responsible scientists are responsibly skeptical…This skepticism is itself scrutinized. Skepticism must be justified and defended. One needs “grounds for doubt” in Wittgenstein’s phrase. Grounds for doubt are themselves challenged. Objections bring forth counter-objections and more evidence. As time passes arguments on one side or the other become strained, fewer scientists are willing to offer them … In this way, questions are settled.