tempproc tempproc No, none of that provides a serious update channel with only security patches. Only the latest major version of Android, iOS and macOS have full security patches. iOS and macOS barely provide any backported patches for older releases, only the highest severity patches.
Android OEMs not on Android 16 QPR2 do not have most of the Moderate or Low severity patches along with being behind on many Critical and High severity patches. Only Critical and High severity patches are backported for AOSP. Many patches are not classified as Critical or High severity. Many high importance privacy and security improvements are not considered bug fixes and not candidates for being backported regardless of severity. Many things would simply be too hard to backport.
Pixels follow along with the stable releases of Android and therefore the firmware, kernel driver and userspace drivers/services for hardware support require the latest stable releases.
Android has 4 major releases per year: 1 yearly release and 3 quarterly releases. Quarterly releases are similar in size to yearly releases and can contain as many user-facing changes. Android 16 QPR1 is the update which overhauled the user interface substantially, not the recent Android 16 QPR2 update.
Non-Pixel Android OEMs don't keep up with the major OS updates and therefore don't keep up with privacy and security patches even if they ship the Android Security Bulletins each month which are only best effort backports, not the complete patches. They're also made available and allowed to be shipped prior to the assigned month which is how our security preview releases work based on the official Android security preview patches which we have access to.