If you work with multi-language projects and want the navigation menu items to be translatable, you can't use the __() function in the PHP class property:
class ProductResource extends Resource{ // You can't do that: protected static ?string $navigationLabel = __('Products');
That code will lead to an error:

Instead, you can define this label in a method getNavigationLabel():
class ProductResource extends Resource{ public static function getNavigationLabel(): string { return __('Products'); }
Then the translations will work without any errors.