Upcoming iOS 16 and macOS Ventura will have ‘Lockdown Mode’ for users who want maximum security on their devices.

Lockdown Mode is meant for high risk users and those who constantly find themselves in risky situations because of their occupation, position or status. The optional ‘protect system’ exercises extreme measures for ‘people who face grave and targeted threats to their digital security’, as per Apple.
When enabled, configuration profiles will be blocked, as well as message attachment types. Wired data connection gets disabled while the device is locked, as are complex web technologies. In short, the device will have very limited system functionality.
Lockdown Mode is set to be introduced in iPadOS 16, macOS Ventura and iOS 16, with Apple promising that they will improve the feature over time. Researchers and developers are invited to test out Lockdown Mode and find out vulnerabilities in the system through a new Security Bounty program.