Xamarin.Forms was like an abstraction helper though, underneath all Renderers. You can/could make CustomRenderers for any custom controls or to access any native needs on iOS, Android and UWP directly. That is how most apps ended up.

Xamarin.Forms was great for getting prototypes going to get things running then going in and taking areas you need to customize, or all controls, and making them platform specific to the targets.

You can still have a shared library that does Content/Pages and most of the work shared. I don't know if Xamarin.Forms was ever meant to be a full solution but it is ok for prototypes and enterprise, for actual consumer shipped apps more customization was needed and CustomRenderers.

The Shared [1][2] setup this way is similar to the handler approach in MAUI where underneath the shared abstraction controls are converted into platform specific but you can do custom ones to override or combine controls.

[1] https://docs.microsoft.com/en-us/xamarin/cross-platform/app-...

[2] https://docs.microsoft.com/en-us/xamarin/cross-platform/app-...