I've had to let go of incompetent managers (I used to manage managers). Maybe I am an incompetent manager myself that no one has discovered, so take my input with a grain of salt.
Competent managers will listen and not jump to conclusions, collaborate with you, ask thoughtful questions about your work driven by curiosity and not because they want to control or micromanage. They will usually be able to catch up and understand what you say and the technical work you do when you explain it (make an effort and you'll be surprised). If there's some tech you work on they do not understand they will educate themselves and ask a bunch of questions trying to catch up so they can help you and assess you fairly.
A more comprehensive answer about how managers are assessed at Google (via Google's project Oxygen):
- Is a good coach
- Empowers the team and does not micromanage
- Expresses interest in and concern for team members’ success and personal well-being
- Is productive and results-oriented
- Is a good communicator—listens and shares information
- Helps with career development
- Has a clear vision and strategy for the team
- Has key technical skills that help him or her advise the team
Your manager should at least be striving to excel at those. Different managers will have different strengths, but the most important thing IMHO is that they care about their team and want to do better.
Competent managers will listen and not jump to conclusions, collaborate with you, ask thoughtful questions about your work driven by curiosity and not because they want to control or micromanage. They will usually be able to catch up and understand what you say and the technical work you do when you explain it (make an effort and you'll be surprised). If there's some tech you work on they do not understand they will educate themselves and ask a bunch of questions trying to catch up so they can help you and assess you fairly.