> Democracy will never be as stable as a regime or dictator

Why never? While I'm not arguing that democracies are inherently super stable (that's empirically false), I don't think that democracies are inherently less stable than dictatorships.

I would think an system that peacefully transitions power with the consent of the governed on a regular basis would typically be more stable than a system where the transition of power is generally a once in a lifetime event dependent on whomever holds the most power in government during the transition.

I can understand the argument that transitioning power is less stable than maintaining existing power structures, but transitioning power is inevitable even if it's to an heir.

Dictatorships aren't stable, dictatorship is stable. Dictatorships involve bloody power strugges that ruin the country and kill people. Dictatorship usually remains, though, because the replacement government is usually another dictatorship - ensuring that when it in turn falls, even more people will die.