That isn't a license to misuse words in a way that forgets your agenda whenever you want.
And no, it's not a misuse of the word.
> Over the past century, “banana republic” has evolved to mean any country (with or without bananas) that has a ruthless, corrupt, or just plain loopy leader who relies on the military and destroys state institutions in an egomaniacal quest for prolonged power.
- https://www.newyorker.com/news/our-columnists/is-america-bec...
> The banana republic term is a derogatory term often used to describe countries plagued with a variety of problems, including a tyrannical or otherwise problematic government or government officials
- https://examples.yourdictionary.com/what-is-banana-republic-...
Etc.