This is the wrong characterization, and in fact it's where monarchies lost out to democracies. Without an organized system of replacement in response to poor performance, autocracies with a poor leader are stuck with that poor leader for life. Ask North Korea how that's going. The upside is that if you have a brilliant leader, then you also get the benefit of that brilliant leader for life. The variance in an autocracy is absolutely huge, and that's their weakness in the long term. Democracies take the edge off, and are intentionally designed to have both less upside and less downside, trading performance for stability. Xi Jinping looks good comparatively because we have gormless losers like Trump and Biden to compare to him to, but he makes plenty of his own mistakes as well (the whole Taiwan situation is a unforced error driven by his own ego, similar to Putin with Ukraine), and we've seen historically what China looks like when it's stuck with a shit leader for decades (Great Leap Forward, anyone?).

Corporations promote people to Principal or distinguished engineer only when they prove their worth by running long running large scale projects.

But when it comes to governing the whole country: lobby, marketing and boom, you are a president for next 4 years, which is anyway not enough to deliver anything big and see the impact. (Except the destruction, destruction is easy to cause)