From what it looks like here, the problem seems to be the optimization for the AMD Navi 5000 series GPU's in macOS. So if that can be relayed to the dev team in charge of that to fix as soon as possible, would be great.
It is not the case that you can expect the same performance in Windows and MacOS on the same hardware. MacOS uses openGL which is a less polished and slower video standard than Windows' DirectX. That's why our published requirements for this an all our games are higher on Mac than Windows.
Which is no to say that CK3's performance on Mac cannot be improved, just to be clear!
This is a different problem than this thread is about.