It's both; the one I mentioned is for system drivers, the one you're talking about is for running applications (which you can also do on a regular non-Halium GNU/Linux using e.g. Waydroid).
I'm sure that if you tell Jolla about a relatively modern mobile SOC with mainline linux support, they'll look into it instead of relying on libhybris.
They can rely on libhybris if they want, why should I care - I just object to calling that "a full-stack alternative", especially when alternatives do exist.
That wasn't modern when they released it in 2020. Jolla chose a little more pragmatism for their hardware in the hope that they actually sell phones to other people than 100% open-source purists. I find it funny when dudes like you go all "well awkshwally" on them...
I use my Librem 5 as a daily driver, and I’m certainly not an open source purist.
What I do care about is that my phone isn’t going to run into obsolescence a few years down the road (due to hard kernel forks and YOLO’ed device drivers that are not going to be updated for newer kernels).