I am not sure you have ALL the code you need to run this in a playground.
Please add these two lines before your ContentView:
import PlaygroundSupport
import SwiftUI
Please add this line after your ContentView:
PlaygroundPage.current.setLiveView( ContentView().frame(width: 400, height: 300, alignment: .center) )
I copy / pasted your code into Playgrounds, added these lines, and I assure you, they work as expected.
Let's Play a Game
Unfortunately, this is a terrible game new XCode programmers have to play sometimes. It's called "What did I do wrong?"
The twist to this game is that sometimes, it's not you!
Many of us do not have the patience to figure out what's really going on in these cases. However, I see the following two clues in your error messages...
apple-ios15.0-simulator
iPhoneSimulator15.2.sdk
Now, I do not know for sure that this is the root of your issue. However, @twostraws spent considerable effort and time last November to update all his tutorials to support the latest versions of XCode and iOS operating systems.
WIthout too much information, it seems you may be trying to run your code using iOS 15.2, and an older simulator. I DO NOT KNOW. These may be generic names for internal software bits.
Do you see my point?
I am running the latest XCode, with the latest iOS simulators. Your code works fine.
This code doesn't work for you. Some clues indicate you may not be running the latest versions of XCode or iOS simulators.