> if developers actually used a small set of common runtimes instead of picking from one of a gazillion slightly different rebuilds All the runtimes on Flathub

> if developers actually used a small set of common runtimes instead of picking from one of a gazillion slightly different rebuilds All the runtimes on Flathub are built on top of the standard fd.o runtime, so the OSTree-level dedup should generally work for them. > Unfortunately (and ironically) it's ill-suited for games, which need to have the latest GPU drivers available, which is antithetical to the whole idea of a stable, universal base system. I believe there's an extension available for the latest Mesa builds, so you can opt for the bleeding edge and then just remove the extension if things break.