There are two modern web views in iOS. The SFSafariViewController is an out of process view. The hosting app doesn't have access to the DOM or what the user enters. The user has access to all of the same cookies, saved passwords, and ad blockers that they would have in Safari. The other (WKviewController?) is your standard embedded web view. It doesn't share cookies, passwords, etc and the embedded app has more access to the web view.