It's rather unreasonable to be annoyed. The maintainers may have entirely different priorities, which is fine. They're also likely being spammed with low-effort bug reports (not yours necessarily but from others).
The great thing about open source projects you can just fix the bug yourself and submit a PR, or fork the whole project if the maintainers won't merge your changes. If you don't have the time or skills yourself then you can even pay a contractor to do it for you.
> It's rather unreasonable to be annoyed.
I disagree. If you discover that a bug that makes an open source library unusable to you, after spending time on learning and using that library, and the authors close the bug as a wontfix, I think being annoyed is quite reasonable, even expected.
If that type of thing annoys you then you should restrict your use of open source projects to those backed by corporations with a paid support business model.
You pay contractors to fix open source bugs? Tell me how that works
Is that a serious question? It works like any contract programming gig. You give the contractor money and in exchange they give you code (including copyright assignment). You can go through a freelancer site like Upwork if you don't know an appropriate contractor yourself.