The best careers are rarely built by tolerating poor leadership indefinitely.gettyLeadership advice usually focuses on helping managers become better leaders. Much less attention is given to a question employees quietly ask themselves every day: How long should I keep believing my manager is going to change?Most people are remarkably patient. They hope difficult conversations will have an impact, that leadership training will make a difference or that the next reorganization will bring a fresh start. Sometimes those hopes are justified. Many leaders do improve over time.But some never do.Change Requires More Than Good IntentionsEvery leader makes mistakes. They communicate poorly under pressure, make decisions they later regret and occasionally disappoint the people who rely on them. None of those moments, on their own, are reasons to give up on someone.The more revealing question is what happens next.Research shows that leaders who are self-aware are significantly more effective because they are more willing to seek feedback, reflect on their behaviour and adjust their approach. That distinction matters. A manager who listens carefully, acknowledges mistakes and genuinely changes their behaviour deserves patience. A manager who dismisses concerns, blames circumstances or insists that everyone else is the problem is sending a very different signal. The issue is rarely that a leader gets things wrong. It is whether they believe there is anything to learn when they do.Pay Attention To Patterns, Not PromisesOne reason employees stay with ineffective leaders is that change often appears possible.A difficult manager apologises after losing their temper. A performance review goes surprisingly well. For a few weeks communication improves, meetings become more constructive and optimism returns. Those moments create hope that lasting change is finally happening.The difficulty is that isolated improvements can distract from consistent patterns.Research suggests that trust develops through repeated experiences of reliability, fairness and integrity. In much the same way, trust is gradually eroded when negative behaviours continue to reappear despite repeated conversations and good intentions. Employees should therefore judge leaders less by occasional breakthroughs and more by whether their behaviour changes consistently over time.Promises are encouraging. Patterns are convincing.Good Leaders Stretch People. Poor Leaders Diminish Them.Strong leaders are not always easy to work for. They challenge assumptions, set demanding expectations and provide honest feedback that can sometimes feel uncomfortable. Those experiences are often essential for professional growth.The difference is that effective leaders leave people believing they are capable of meeting those challenges.Research has linked destructive leadership behaviours with lower wellbeing, higher burnout, reduced engagement and greater employee turnover. Employees who experience ongoing disrespect, unfair treatment or psychological insecurity are not simply less satisfied at work. They often begin questioning their own competence and confidence.Work should test people’s abilities. It should not steadily undermine their sense of self.If a leader consistently leaves employees feeling smaller, more anxious or less confident than they were before, the consequences extend far beyond day-to-day job satisfaction.Sometimes Leaving Is The Wisest DecisionMany employees view leaving a difficult manager as admitting defeat.In reality, it is often an acknowledgement that leadership is a relationship, and relationships require commitment from both sides. Employees can offer feedback, demonstrate patience and make genuine efforts to improve communication. What they cannot do is force someone else to become more self-aware or more willing to change.Research continues to show that people are far more likely to leave managers than organisations. Leadership quality remains one of the strongest predictors of engagement, job satisfaction and employee retention. That should encourage employees to ask a more evidence-based question. Rather than wondering how much longer they should wait, they should ask what objective evidence suggests the situation is genuinely improving.Hope is valuable, but it is not a substitute for evidence.The best careers are rarely built by tolerating poor leadership indefinitely. They are built by recognising the difference between leaders who challenge you to become better and leaders who repeatedly prevent you from doing your best work.Resilience is an important quality. So is knowing when perseverance has become persistence without progress. Sometimes the bravest decision is to stay and help a leader grow.Sometimes the wiser one is to recognise that they never will.