After several decades of working in the US the main problem from my perspective is that delusional employees, favored and enabled by management, destroy a lot of trust among their coworkers and that adds a lot of workplace stress for many people.
You've said, "the main problem". Are you talking about something that affects most of the working population?
However I think the specified hierarchy is not required for most workplaces. There is a lot more variety in where the sociopaths reside, and I consider both the clueless and sociopaths to be delusional. Deluded might be a better term for both.
0. https://www.ribbonfarm.com/2009/10/07/the-gervais-principle-...