Easy, just get a case for your case.
I’ve use the tan leather case for over a year, it will scratch easily, but then the scratches go away just as easily. I know everyone has their own likes and dislikes, but I like how the case looks overtime. An actual scratch doesn’t look good, but they do go away very easily, at least light scratches
I think you misunderstand what cases are for,
they protect your iPhone, so the case gets scratched instead of your phone, if your case gets damaged or looks terrible after a while, you buy a new one, simple
BTW, the best iPhone case you can use, is the original box it came in
BTW #2, do you think, every morning, about what iPhone thread you will start ?
I'm not too worried about a patina. Would be nice if there was something similar to how liquid screen protectors work that you can use on glass to protect the screen from scratches... instead you apply it to leather and it protects it from scratches or gives it self healing properties.