This is a deeply frustrating and energy-draining situation. Thank you for sharing it so candidly. The fact that your motivation has taken a hit is a completely natural and valid response to poor leadership. You are not the problem here.

I'm a founder based in Seoul, so I can't comment on the specifics of US corporate culture or the internal politics at your company. However, I believe the framework for making a decision in such a situation is universal. When I or my team members have faced difficult career choices, I've found it helpful to analyze it through three lenses:

1. The Learning Lens: Are you still growing? Despite your manager, are you still acquiring valuable skills and experiences that you couldn't easily get elsewhere? Is the work itself still challenging you in a positive way?

2. The Mission Lens: Do you still believe? You said you still care about the mission. The question is, how much? Is your belief in the mission and the product strong enough to endure this manager for another 6, 12, or 18 months? Can you still find a way to contribute effectively to that mission?

3. The Life Lens: What is the daily cost? This is the most important question. What is the daily tax this situation is imposing on your mental and emotional health? Is this cost sustainable over time? Is the person you are becoming in this environment—perhaps more cynical or stressed—someone you respect?

No one on the internet can answer these questions for you. My only advice is this: take an hour, write down your honest answers to these three questions. Don't decide today. Put the paper away, and read your own words again in a week.

Often, seeing your own thoughts written down, separate from the daily frustration, makes the path forward surprisingly clear.

Ultimately, your career is long, but your life is happening now. Your well-being is the most important asset you have. Making a conscious choice for yourself, whatever that may be, is a victory in itself. Wishing you clarity.