Security yes. Agree 100%. Once a device vendor stops committing to firmware security, GrapheneOS considers the entire device e-waste as a precaution. Freedom, I think LineageOS deserves some credit here. Pixel 3 is already obsoleted by GrapheneOS because of this, a little over 3 years after purchase. You're not free to choose running the latest Android security update regardless of vendor security patch level. For long term support, you need LineageOS. The 2013 Nexus 7 has latest security update with LOS 10 years after release. The post vendor support is what made me try my first custom rom. And ideally I'd like a consistent experience, with the same OS on all my devices.

No, this is incorrect. The Android patch level includes firmware and drivers. The 2021-11-01 patch level is the last one obtainable on the the Pixel 3 and Pixel 3 XL. LineageOS and other alternate operating systems mislead users about the patch level. The Android patch level is not split up into vendor, firmware, etc. It exists to communicate the overall patch level of the device. The way LineageOS splits it up also doesn't change that they're communicating inaccurate values to users. You do not have the latest patch level there. You only think you do because it's a string that can be set to any value.