I attempted installing LineageOS on an older LG phone. ~3 hours later and nothing to show for it. Did I even successfully root it? Was I using adb correctly? #shrug
I definitely don't think this is in the realm of the impossible, but simpler (and ready-out-of-the-box) alternatives are desperately needed if we want to combat Google/Apple/etc. and their stranglehold on mobile computing.
An instance of one.