I was made aware from this GrapheneOS Mastodon post [1] that only the most recent major Android version contains all security relevant updates while previous versions only receive some Android Security Bulletin (ASB) patch backports.
Looking at Google's Pixel support timeline [2] and the general rule not to use "insecure devices" does that mean I should better upgrade to a newer device once the "Guaranteed Android version update" date is reached even though my device is still within the "Guaranteed security updates" timeframe?
[1] https://grapheneos.social/@GrapheneOS/111169964801604661
[2] https://support.google.com/pixelphone/answer/4457705