iOS 14:

iOS 14 doesn’t show extra separators below the list by default and to removing all separators, you need to use a LazyVStack inside a ScrollView instead. (because iOS is NOT supporting appearance for SwiftUI lists anymore).

iOS 13:

⚠️ This method is deprecated and it’s not working from iOS 14

No need for Section or .grouped style!

There is a UITableView behind SwiftUI’s List for iOS 13. So to remove

– Extra separators (below the list):

you need a tableFooterView and to remove.
Note that iOS 14 doesn’t show extra separators below the list by default.

– All separators (including the actual ones):

you need separatorStyle to be .none

init() {
    if #available(iOS 14.0, *) { 
        // iOS 14 doesn't have extra separators below the list by default.
    } else {
        // To remove only extra separators below the list:
        UITableView.appearance().tableFooterView = UIView()
    }

    // To remove all separators including the actual ones:
    UITableView.appearance().separatorStyle = .none
}

var body: some View {
    List {
        Text("Item 1")
        Text("Item 2")
        Text("Item 3")
    }
}

Note that it eliminates all tables/lists’s separators. So you can toggle it in a methods like onAppear() or etc. as you wish.