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).
What I was trying to tell you with my original reply to you is that Jolla chose a different point on the free/pramatic curve of available SoCs. They selected a phone that's more likely to be used by average people rather than a fully open one. (You can still see in this very thread, complains about the high price for what it offers, showing they haven't fully succeeded, at that.)
Pointing out that they still rely on Android drivers for booting the thing is a little tone-deaf from my perspective when they're basically choosing a different path towards a similar goal to Purism and other alternative mobile vendors: higher availability of non Google, non Apple mobile devices. Perfect is the enemy of good and all that. And like I explained the reason for their choice is not nefarious but a pragmatic one.