I had very different experiences.
I worked for an acronym company in which the majority of "leaders" were smart, driven, capable, and despite mistakes that anyone can make, it would have not been fair to call them incompetent.
Some were incompetent, they got promoted into positions of responsibility and power when the company was scaling up so fast that they could not hire externally for those positions fast enough, and the internally vetting was weak. Then, they created their "network of power" within the company and they went on working incompetently for a few years. And then there were people like my former boss who are idiots with an academic title of some weight. Many such cases.
I then worked for a huge company, but not an acronym one, and at the Director/VP/C- level there are pockets of incompetence that are difficult to explain to others and to accept as possible.
CTOs that know little about technology, VPs that ask LinkedIn for surveys of employer retention to make the case that they were not losing more people in a year than, say, Google, but not accounting for the fact that we could not hire anyone for months while Google is so worried about false positives that they reject plenty of very viable candidates. The same slides presented at each all-hands meetings not to reinforce the vision or goals, but because they are too lazy to prepare new slides for an audience of 500 people, who looked at themselves asking: again?
One might say that they are competent at navigating company politics, which is like saying that the employee sleeping with their bosses are competent at getting promotions.
When I worked in academia (not in the US, if that matters), there were plenty of
tenured professors that I would say were in the bottom 5 or 10% in terms of competence, research plans, management of students and postdocs, when compared to all postdocs in the same research area. Useless professionals that schemed their way through academia. And everybody knows that, but people who are inside have nothing to gain by exposing them, and people who leave academia they say, well, not my problem anymore, f them.
In my home country, the vast majority of politicians are incompetent outside of their core competence, which is getting votes.
I was under the impression, when I was younger, that I was wrong whenever I saw someone in a position of power, be it in the private sector or public office, who I saw as incompetence. How is it possible, I was asking myself, that somebody can get promoted, assigned huge responsibilities, be accepted by their peers when they are not at their level or at the level of competence required by their position.
But it is very possible and in reality quite frequent.