It is something I think that is truly awesome to see, and like you said, it has been in the spirit of free software. I am hoping that with more folks with a Librem (and Pinephone), that the software will mature even quicker.
It is hard to overstate the importance of this, no matter how you feel about Purism's hardware or the company...
Whether somebody personally prefers the Librem 5, or the Pinephone, or is holding out for some future higher-spec Linux smartphone - chances are that the work Purism did with phosh, phoc etc will benefit the entire community greatly.
Nipick : Posh is not related to GNOME shell in any way. It is a from-scratch implementation of a mobile window manager in C on top of Wlroots (while Gnome is JavaScript on top of Mutter)
Also, phoc is the compositor and window manager; phosh is the shell-equivalent.
The Sailfish OS and Mer communities have had a working plumbing and porcelain stack for years (granted Sailfish's UI is not fully opened source) but Purism insisted on bootstrapping their own instead of building on those. I feel like they could have forced Jolla's hand to open source the last bits of their proprietary UI and everybody would have been happier.
See also: https://source.puri.sm/Librem5/community-wiki/-/wikis/Freque....
Regarding the whole stack, I recommended reading https://puri.sm/posts/what-is-mobile-pureos/
I was sure I saw in a different discussion that it's the other way around. Maybe you have a link ?
Once it works it will be just a regular V4L2 device on the system, there are plenty of GNU/Linux apps that can consume it and there are now even mobile-focused ones like https://git.sr.ht/~martijnbraam/megapixels/ and https://gitlab.gnome.org/jwestman/camera
I am so glad the guys at Purism reached this point and did not give in to the folks who said the project would fail.
Phosh, their GNOME-derived shell, is now also used by many distros on the PinePhone, which is exactly the spirit of free software I wanted to see for the smartphone when I originally backed this.