I think this is probably better characterized as "efficiency erodes resilience". You can have stability if there are no perturbations. However, if there are, and you have optimized for a regime where there are not, you are very exposed to risk. This is pretty much Table's notion of antifragility as well as the study of resilience engineering.
There's an engineering version of "stable" that might be useful here to draw lines between the three or so different concepts being discussed. A "stable" system is one that will return to the same resting state when perturbed. One can have "equilibrium" in an unstable system, e.g. balancing a broomstick on one's hand, but the system will not return to that equilibrium if perturbed.
This idea also helps when thinking about local/global (I'd argue most of what we do is local optimization of minima, and what challenges us is when the assumptions about locality of the phenomenon are challenged enough that we can't guarantee that stability).
And the idea is also applicable to trajectories rather than singular points: if you change your starting point by an epsilon, would the trajectory be vastly similar or a bit different? or very different? cue in Lyapunov fun and Lipschitz continuity[0] as a metric and, to a lesser extent, conditions for chaotic trajectories to emerge.
It's not a binary opposition. In control theory you can make a system unconditionally stable, or you can allow a little oscillation around the ideal, or you can make it unconditionally unstable so the tiniest hint of noise drives it to an extreme.
In some systems you want to generate constant oscillations, so your system can be in stable perpetual dynamic equilibrium producing a nice sine wave.
I think you mean resilient when you say stable: A stable system NEED not get back to resting state by itself. A resilient one does.
Along these terms, I think equilibrium doesn't really make sense - it means stability in many definitions. From the top google result:
> Equilibrium is defined as a state of balance or a stable situation where opposing forces cancel each other out and where no changes are occurring. An example of equilibrium is in economics when supply and demand are equal. An example of equilibrium is when you are calm and steady.
sigh, someday we'll have auto-correct that just works. Doesn't even need to be AI, just use words in the current page. Heck just use contextual info such as the capitalization. Somebody, please?
