Hey Brian,
I have done some projects so far using SwiftUI and used a very similar approach like you had with the ObservableObject ViewModel class however I call mine a store so in this case it would be CategoryDetailsStore. I got this MVC styled approach from a medium article (https://medium.com/movile-tech/swiftui-and-architectures-mvc-9af08239c116). Is the pattern you are going to use for the travel discovery app MVVM ?
Thanks,
Aidan