Can LineageOS do major upgrades without needing support? (so once it's installed you never need to reinstall, and you can keep it safely up-to-date forever by clicking a button every so often - like Silverblue)
No. Not even Google Pixel can promise error-free major upgrade jumps e.g from Android 12 to 13.
But on LineageOS you can update through all the updates for the major Android version (mostly ASB fixes and some new features here and there) by clicking a button from the Updater menu, courtesy of Android's A-B dynamic partitioning update system.
But on LineageOS you can update through all the updates for the major Android version (mostly ASB fixes and some new features here and there) by clicking a button from the Updater menu, courtesy of Android's A-B dynamic partitioning update system.