/etc configuration instead of the insanely bad system properties crap, glibc instead of bionic (which has even worse POSIX compliance than Windows), ld instead of linker, FHS, not having a batshit insane No-Sockets rule, not needing to port software that already compiles and runs on GNU/Linux, X11/Wayland/Arcan, system services aren't entangled with Java, normal IPC mechanisms instead whatever the fuck binder is. The list goes on.

Android (and by extension GrapheneOS) uses Linux as a kernel, but it lives in its own world and is completely unrecognizable. I'd say it's even more alien than macOS. For most users, the differences don't matter. If you're a programmer or a sysadmin with reasonable expectations, you feel like a fish out of water very fast. And I cannot honestly the changes are for the better.