Correct, our extended support releases provide all the AOSP and GrapheneOS changes. It's unclear if extended support will continue for the Pixel 4, Pixel 4 XL and Pixel 4a after the release of Android 14 but we'd like to continue it. However, firmware and most drivers won't get updates. To temper expectations we generally make clear ESR will continue 12 months after the last major OS an EOL device receives. Anything more is a bonus, however it could be less dependent on regressions.

Ideally you should be moving to a 7th generation Pixel from the 4th Gen. There are only a couple days to a couple weeks remaining before the Pixel 4a is behind on security patches regardless of your OS choice. Our extended support releases are only harm reduction, not a solution.

Receiving patches for all known serious vulnerabilities is part of the basics. You won't have that on an end-of-life device. Continuing to provide all the AOSP and GrapheneOS changes for end-of-life devices via extended support releases fundamentally can't provide this.

The past 2 generations of devices have 5 years of proper support from launch. Only the Pixel 5a and earlier had 3 years of proper support from launch. It stopped making much sense to buy them once the Pixel 6 was released if you want to use devices for a long period of time.

If budgets are a concern then the Pixel 6a should be a target. It would make little long term sense to buy anything below this.