I have a Catalyst-enabled app with a UITabBarController for view switching and a custom "tab bar" (actually a UICollectionView).
In my case, I wanted to hide this new tab bar and side bar. Here is the workaround I needed to do to accomplish that, as setTabBarHidden didn't work for me. Posting here in case it helps anyone else.
internal class MainTabBarController: UITabBarController {
internal override func viewDidLoad() {
#if targetEnvironment(macCatalyst)
mode = .tabSidebar
sidebar.isHidden = true
#else
setTabBarHidden(true, animated: false)
#endif
}
}