Re: Horsecrap
LineageOS. Both those devices are now over 5 years old. Thank yourself lucky you didn't buy apple, they would have dumped you well before the 5 year mark, and an dumped apple device doesn't get ANY system updates.
Your 5year old nexus devices however will have been updated to run the latest web browser and WebKit library for other apps to use) the latest email and gmail apps, and every other store updatable system app too, google would have squirted down the latest SSL libraries via Google play services too and would have sent you play protect (on device scanning for malicious apps).
So yes, you got a hell of a lot more than a apple user would above got, your updates were delivered seamlessly without you noticing or needing a full OS update to get them.
Are you missing out on kernel fixes, yes, but it's unreasonable to expect them on a device that cost less than £250 5 years ago.