One of the security models built into ChromeOS is a well defined attack surface. It is not for general apps, it only runs Chrome (and things within an Android e

One of the security models built into ChromeOS is a well defined attack surface. It is not for general apps, it only runs Chrome (and things within an Android environment on newer machines). There is a comprehensive auditing and monitoring solution combination (Auditd & SELinux) that is hardened above what is normally possible on Linux desktops and servers. When an audit violation is detected ChromeOS forces an update an reboot to the new version (which takes seconds and feels almost like you've been unexpectedly logged out). All without losing any data except for unsubmitted form contents. Even if an update isn't available, the writable part of the system (not user data) is completely wiped limiting the ability of malicious actors to persist anything. It's not a panacea but it is way more aggressive and seamless than any of the major operating systems could possibly do.