Whatever solution you pick for iOS dev: Flutter, React Native, Xamarin etc etc, in the end we will always meet the same thing: iOS SDK. And iOS SDK only runs on Mac, unlike Android.
Unless Apple decide to port their SDK to Windows/Linux (which I believe will not happen), you can't practically avoid Mac.
Whatever solution you pick for iOS dev: Flutter, React Native, Xamarin etc etc, in the end we will always meet the same thing: iOS SDK. And iOS SDK only runs on Mac, unlike Android.
Unless Apple decide to port their SDK to Windows/Linux (which I believe will not happen), you can't practically avoid Mac.