Why do many capable and intelligent leaders fail?
Sometimes a smart leader simply fails to adapt, whether to a different intensity and pace, new pressures and expectations, or behaviors and work styles, often assuming that his or her own skills trump everything else.
Leadership failure can be caused by many factors including the leader's lack of experience, poor communication skills, and conflicts with other leaders. Leaders need to put their best foot forward at all times so they do not risk losing the respect of those around them or undermining their authority as a leader.
Highly efficient leaders often suffer from tunnel vision.
Rather than strategize or look at the bigger picture, many highly efficient leaders prefer to grind their way to success. This lack of strategy means they are often unable to achieve results despite their desire and effort.
Leaders start to fail when they get too focused on the achievements and the numbers. Without the culture and the values to direct them, leaders (along with the team) follow misguided and misconceived goals which can quickly lead them to their downfall.
Recap: 4 Reasons highly intelligent people fail
They are born into bad circumstances, poverty, a toxic family, a lack of resources and opportunities. They suffer from mental illness, which creates myriad other barriers to career advancement and better paychecks. They lack people skills or are arrogant.
“Self-doubt is why we don't change and why we don't take action. Self-doubt is a story we tell ourselves to justify why we can't do something and why it's not possible. That is the reason why smart people often fail. When you're really smart, you're good at predicting all the negative outcomes.
When the trust that followers have in a leader begins to erode, that leader loses power. Behaviors or bad leadership habits developed by a false sense of control can undermine credibility with shareholders, board members and employees.
When leaders fail, they see it as a momentary event, not a life sentence. It's not the end of the world, but a chance to project yourself ahead and see yourself having overcome and persevered. Failure disciplines our expectations. Failure can be helpful in learning how to manage expectations.
Why do leaders fail? They fail because they are human and can make mistakes regardless of how good they are at what they do. There is also a possible scenario where the leader's failure is caused by the incompetence of others.
We make mistakes all the time (everyone does). But the best people – the best leaders – learn from them. Great leaders also admit when they've made mistakes. Contrary to a widespread belief among managers, bosses, and leaders of all stripes, admitting your mistakes strengthens your position in so many ways.
Why do new leaders fail?
The major reasons for failure in the new job are:
52% fail to build teamwork with staff and peers. 33% are unclear about what their bosses expect. 25% don't have the required internal political savvy. 22% there's no process to assimilate new leaders into the role.
When someone's extremely successful, it's normal to think that they were always successful. But that is usually far from the truth. Even successful people have had their fair share of failures in their lives and had to fail time and time again to finally have their big break.

Failure is, inevitably, part of any success story. Those at the top have pasts littered with start-ups that went under or ideas that never got off the ground. The greatest risks yield the greatest reward, but you have to risk it over and over again until you create something that sticks.
You might not learn the value of hard work.
A number of Quora users mentioned that intelligent people feel like they can get by with less effort than other people. But a high IQ doesn't always lead directly to success, and highly intelligent people may never develop the perseverance required to succeed.
Companies consistently struggle with (1) unclear direction on strategy and values, which often leads to conflicting priorities; (2) senior executives who don't work as a team and haven't committed to a new direction or acknowledged necessary changes in their own behavior; (3) a top-down or laissez-faire style by the ...
An incompetent leader lacks trust and hence, ends up micromanaging and giving a tough time to his team members. An incompetent leader will not trust his employee to complete the task assigned to him, and end up chasing the person and building unnecessary pressure all the time.
Science agrees. A 2016 study published in Journal of Research in Personality found that people with high IQs tend to procrastinate more, if only because high intelligence affords the luxury of waiting to begin a task.
Past studies have also shown that high IQs are comparably reliable in predicting academic success, job performance, career potential and creativity. Antonakis says high IQs are particularly notable predictors for success in highly complicated, skilled occupations like physicist, engineer or even neurosurgeon.
Intelligent people, though, tend to be characterized by insecurity. They have a high level of personal response, reflection, and discretion. None of these things makes an impact. Plus, we live in a world where people still see insecurity as a negative characteristic.