I’m not hearing that. Safari has its share of CVEs, including many of the jailbreak methods of the past, meaning one click to root the device. Apple isn’t any better at software than any other html engine vendor. And by having a monoculture on iOS, every time there’s a WebKit bug 100% of iOS users are guaranteed exploitable. There’s zero net security benefit to banning Gecko and Chromium (and any upstart innovators).