Hijacking as I've done on other posts. In my country all 3 major tellcos needed to verify phones can call emergency on VoLTE.

FP5 does this. For whatever reason the telcos cant "conform" that (its not sold here but important and DOES work) so the device is blocked at a network level.

Not blocked just for calls but even data.

Phone is now a brick. Double brick once the Android changes roll through.

The issue with Ubuntu Touch is that unfortunately it uses an outdated Android kernel (which is also usually not receiving security updates) and a Halium abstraction layer to access the closed source binary blob Android drivers for the phone’s hardware. It also requires that it be installed on top of an existing Android install, so in all it’s more of Linuxified layer on top of Android, which means it’s not truly escaping the control of the Android/Google ecosystem.

UBPorts also appears to inherit the use of CLA's from Canonical:

I'm very much not a fan of CLA's., which SailfishOS also employs.

The advantage of PostmarketOS (even though it is not ready as a daily driver for the average person), is that it uses the upstream Linux kernel with open-source GPU/hardware drivers, not an Android kernel to access the outdated proprietary GPU/Hardware blobs.

no they don't. they do have a partnership with Murena, which sells them preinstalled with /e/, which is a degoogled Android ROM. there is a Ubuntu Touch port available for some Fairphone models though.