An end-of-life Xiaomi device with no privacy or security patches for the firmware, Linux kernel, drivers and HALs for years doesn't provide the bare minimum for protecting user privacy and security.
It would theoretically be possible to port it to a newer kernel but that's not within the scope of LineageOS. It doesn't do that so there aren't Linux kernel updates since the kernel branch has been end-of-life for years already. It would also theoretically be possible to rewrite all the userspace drivers and HALs, but it's not being done. The firmware is a different story since it's usually signed and requires vendor support. It's important too since it's exposed to remote attacks via cellular, Wi-Fi, Bluetooth, NFC, GPU (web browsers, etc.) and more.
> An end-of-life Xiaomi device with no privacy or security patches for the firmware, Linux kernel, drivers and HALs for years doesn't provide the bare minimum for protecting user privacy and security.
Your very rigid view of the world is so distorted to the point of being absurd. You know damn well that the vast, vast majority of spying on Android is done in userspace.
A good OS that allows you to remove permissions from apps and further isolate things does a lot for privacy.
I respect your desire to refuse supporting anything but pixels, but please don't pretend that alternate OS on old devices don't improve privacy and security.
Frankly, that kind of rigid attitude/black and white thinking might be why you find it so hard to collaborate with upstreams.