The chaos monkey is pointedly unsophisticated, but a system that can reliably survive its attack is likely to be very sophisticated. Airline pilots are effectually faced with a chaos monkey in their recurring simulator trainings and as a result have a very sophisticated skill set (indeed, one most of them will never actually need, but train for anyway, for obvious reasons).

Also, I take issue with it being “destructive”. Compute resources are effectively free on the margin (at least at the scale that concerns us here) and ephemeral. Killing such a process doesn’t meaningfully destroy anything of value.

Assuming perfect systems that never fail seems more immature, no?

That the industry is finally maturing in to a field that capitalizes on the unique properties of its medium?

Seems analogous to load testing a physical structure. At first, that probably seemed unnecessarily risky, but in retrospect, you want to build robustly enough that even fairly excessive/destructive loads have no real impact.

Why do you think this is one of the "more sophisticated" testing practices?