Why do other tab views render on TextField focus?

I have an app with 4 tabs. Each tab has its own view model. The user flow is:

1. Open app

2. Click on tab 4

3. Select the TextField

My expectation was that on tab 4 selection the onAppear's would execute for that tab. Then on textfield selection nothing would happen.. instead all tab views are rendering.

Why and how do I make those other tabs not render on selection?

Her is the user flow results and code:

// ON LOAD
1 simple view appear
1 get people
tab 1 appear
1 get people

// SELECT TAB 4
4 simple view appear
4 get people
tab 4 appear
4 get people

// FOCUS TAB 4 TEXTFIELD -> ALL TABS RENDER

! Why are these tabs rendering?

2 simple view appear
2 get people
tab 2 appear
2 get people
3 simple view appear
3 get people
tab 3 appear
3 get people
tab 1 appear
1 get people
1 simple view appear
1 get people



Content View

Code Block swift
import SwiftUI
import CoreData
struct ContentView: View {
  @Environment(\.managedObjectContext) private var viewContext
   
  @ObservedObject var viewModel1: ViewModel = ViewModel()
  @ObservedObject var viewModel2: ViewModel = ViewModel()
  @ObservedObject var viewModel3: ViewModel = ViewModel()
  @ObservedObject var viewModel4: ViewModel = ViewModel()
   
  var body: some View {
    TabView {
      SimpleView(viewModel: self.viewModel1, people: viewModel1.people, num: 1)
      .tabItem {
        Text("1")
      }.onAppear{
        print("tab 1 appear")
        viewModel1.getPeople(num: 1)
      }
      SimpleView(viewModel: self.viewModel2, people: viewModel2.people, num: 2)
      .tabItem {
        Text("2")
      }.onAppear{
        print("tab 2 appear")
        viewModel2.getPeople(num: 2)
      }
      SimpleView(viewModel: self.viewModel3, people: viewModel3.people, num: 3)
      .tabItem {
        Text("3")
      }.onAppear{
        print("tab 3 appear")
        viewModel3.getPeople(num: 3)
      }
      SimpleView(viewModel: self.viewModel4, people: viewModel4.people, num: 4)
      .tabItem {
        Text("4")
      }.onAppear{
        print("tab 4 appear")
        viewModel4.getPeople(num: 4)
      }
    }
  }
}

Model

Code Block swift
import Foundation
struct Person: Identifiable, Equatable {
  let id = UUID()
  let name: String
}
class ViewModel: ObservableObject {
  @Published var people: [Person] = []
   
  func getPeople(num: Int) {
    print("\(num) get people")
    DispatchQueue.main.async {
      let person = Person(name: "Hank \(num)")
      self.people.append(person)
    }
  }  
}

View Model

Code Block swift
import SwiftUI
struct SimpleView: View {
   
  @State var text: String = ""
  @State var viewModel: ViewModel
  var people: [Person]
  var num: Int
   
  var body: some View {
    VStack {
      TextField("Enter text", text: self.$text)
       
      ForEach(viewModel.people) { person in
        Text(person.name)
      }
    }.onAppear {
      print("\(num) simple view appear")
      viewModel.getPeople(num: num)
    }
  }
}