That is the question. At least a partial answer is that people running the world are way more stupid than most of the regular people. Trying to run the madhouse that is humankind is a job for the nutty. Or an unsavory job for a very respectable person, who takes the job out of professionalism and a sense of duty that somebody has to do this crap job no matter how unpleasant it is. Those seem to be the minority and people with personality disorders and apparently a lack of appropriate knowledge jockey for power to compensate for self realized lack of somethings they know are missing vs the rest of the population, but being fools don't realize what is missing. Compensating by going after all that shines and glitters is the standard response of a person that suffers from personality disorders. They explain to themselves that being in a superficially coveted position earns them respect. So they make themselves slaves of the perceptions of others. In superficial examination, which is the only mode available to people, who lack understanding of how things work. The lack comes from the incomplete maturing hampering processing of data. If you can't connect the dots between a and b you develop a twisted world view. When you late need to apply a, b or their relation and have messed up you are gonna fail even harder and develop even stranger misconceptions. Repeat often enough without help, intervention or realization that observed facts don't connect with previous deductions you will go to a breakdown. These kind of people are often locked up in mental institutions. A real problem is that these people will by like rain men of pursuing what glitters. Their sole goal is to excel so they work hard and are often competent within their limits. They often perform medium level and some top level difficult tasks excellently and rise in status in organizations. It is a real problem for companies and owners of companies to get bosses, who aren't magpies going for shiny things like madman making money for everyone, but not letting them go too far beyond their capabilities. It is way too common to promote these types to too high positions, where they are called for to make decisions that is beyond their capability. Instead crucial things won't get performed or are twisted to insanity, because that is what you get, when the insane call the shots. AKA the world today.
One widely known behavior type for fools promoted too far is the options of the leaders. When the goal setting for triggering big pay days in the form of options for a foolish boss allows running down a business just so that the boss gets fast easy cash, too many do it. We all know what has happened as a result. The common sense cure would be to subject boss wannabes to properly done psychological evaluation. The thing is where do you find a competent enough psychologist to do the testing? It is not enough to be a psychologist by training, in order to understand the sensibility or lack thereof of the tested person the psychologist should not just perform tests, but interview the test subject deeply enough. In order to be able to properly evaluate the test subject the psychologist needs to understand the test subject and what it is that they should do in their line of work. That means being competent in another profession. Not easy considering how long it takes to train a psychologist. All of this goes against one of the basic principles in sciences that the untrained should not be in a position of power over the trained as a rule, What does a psychologist know of leading, managing, being a leader etc? That is why there are so few suitable psychologists and why they charge astronomically. No wonder then that so many cuckoos get to the top without having been tested properly. Then the shit hits the fan for everyone. Multiply this to national leaders and you get the even more foolish than your average sufferer of personality disorders bosses. In democratic societies you don't even need to graduate elementary school to be elected and you certainly don't need to know anything. Thus cultivating the foolishness of the decisions. A case in point the minister of finances in Finland is a nurse by training. What does a nurse know about economy? Or leading. All of Europe is in shifting sand, because of that one woman at the moment. Why is the interesting story. The answers are many and stupidity and several types of failing ethically, morally, logically etc. are among them.