Earlier quoted context omitted.
The OS in this case has nothing to do with not being able to be ported to other phones. Google is one of the few who will pay extra to Qualcomm for the ability for users to flash their own signing keys. Lineage does not support one of the most important security feature of any modern smartphone, lockable bootloader and verified boot. Lineage might be more privacy respecting than Googles Android, but far behind regard…
There's no point in using LineageOS after they dropped PrivacyGuard instead of expanding it. You start going down this road and suddenly you'll have a phone that doesn't pass SafetyNet anymore. You have to use 3rd-party applications and probably a ROM made by a random internet user not affiliated with LineageOS because they drop support for devices all the time. The phone manufacturers bribe ROM developers to do that…
Lineage is also so frigging annoying how they just drop old phones. They won't even provide the last good build or previous builds. Really bad thinking over there in general I guess.
:(