I view this as a complete failure of the project: to bring back old phones to an usable state.
I've always objected that postmarketOS, while great, fails at being real-world usable.
AFAIK, there currently is not a single phone which is 100% supported, and not a single phone that can make calls, send/receive texts, and browse the internet.
You know, the things that you would use a phone for.
One of their flagship phones, the google nexus 5, only partially works and btw, last time I followed their installation instructions, it didn't boot.
I still admire their accomplishments, but they failed to deliver on the original core idea.
I really hope that they manage to deliver... In the meantime, if you want to make calls, you're stuck to regular phones.