alt Hacker NewsGrapheneOS is not solving the actual interesting problem (running on an entirely mainline kernel, just like on x86). It's effectively a hardened variety of LineageOS/AOSP, hence entirely reliant on device-specific downstream kernels/BSPs that will never see a feature update.
BTW, hardware support on postmarketOS "community" class devices has seen some nice improvements as of late. Once these improvements meaningfully stabilize (avoiding the risk of regression/breakage; there's been some of that even in the recent testing for the 2025-12 stable release) it's quite possible that some "community" devices might finally reach "main" class, marking them as OK for daily-driver use. Something to watch for as we approach 2026-06.
>GrapheneOS is not solving the actual interesting problem
Consumers don't care how interesting the developer's problems are. They want their own problems to be solved and GrapheneOS does a better job of that.
>running on an entirely mainline kernel
Google already did that work years ago. Android will work on a mainline kernel. Just like with x86 the mainline kernel needs to support the hardware e you want to use though.