[ndiddy]

You can stay on Sequoia and still get security patches. They released 15.7.4 a few days ago. https://support.apple.com/en-us/126349

[burnt-resistor]

While it works for macOS, that strategy doesn't work for iOS. Apple has broken their contract of 2 supported OS versions to force people onto iOS 26 unwillingly as a deliberate strategy by sneakily not releasing iOS 18 security updates for all devices. A manufactured Hobson's choice between usability and security updates.