AnyMyProtocol.swift

import SwiftUI

protocol MyProtocol {
    associatedtype MyAssociatedType: StringProtocol
    var myAssociatedType: MyAssociatedType { get }
}
struct MyConformingType: MyProtocol {
    var myAssociatedType = "Hello"
}
struct MyOtherConformingType: MyProtocol {
    var myAssociatedType = "World"
}

struct MyType {
    var anyExample: any MyProtocol = MyConformingType()
    var someExample: some MyProtocol = MyConformingType()
}

struct ContentView: View {
    @State var myType = MyType()
    var body: some View {
        VStack {
            Text("myType.anyExample: " + String(describing: type(of: myType.anyExample)))
            Text("myType.someExample: " + String(describing: type(of: myType.someExample)))
            Button("Change") {
                myType.anyExample = MyOtherConformingType()
                // Will not compile as type is not 'some MyProtocol'
//                myType.someExample = MyOtherConformingType()
            }
        }
    }
}