It's normal human variation.
A chunk of any group of humans just wants someone to confidently tell them what to do.
Unfortunately intelligence and confidence is usually an either/or thing.
Someone who knows their shit and is intelligent is aware of possible flaws with their plan, and is pre-emptively coming up with possible fixes if needed. They will never be 100% confident.
But an idiot with no idea what they're talking about?
That's exactly the type of person to always be 100% confident.
Our monkey brains are wired to think that if someone is that confident, they'd be dead if they weren't also capable.
Generational wealth/power isn't unique to humans, but inherited wealth/power is. With everything else if the powerful parent is gone, the nepo kids lose all status.
That's the disconnect from how we evolved and how we currently live. Especially when we stop educating people so they can think past instincts