iOS's only security issue is users not updating and being vulnerable to well known vulnerabilities. Neither iOS nor Android will survive a truly targeted nation state attack, but for most people 0-days aren't worth protecting against.
The only exception to this is the checkm8 vulnerability, which can be performed on an A11 and older chips (so iPhone XR/XS/XS+ and 11/11 pro/11 pro max aren't vulnerable) from DFU mode, which doesn't need the device passcode.
The only exception to this is the checkm8 vulnerability, which can be performed on an A11 and older chips (so iPhone XR/XS/XS+ and 11/11 pro/11 pro max aren't vulnerable) from DFU mode, which doesn't need the device passcode.