What’s missing in this article (or at least as much of it as I could read) is that much of the software listed has alternatives. For instance, bash can be replaced by a combination of some other shell (fish, zsh, dash . . .) and some other scripting language (python, perl . . .). There are other compression algorithms than xz, even if they’re less efficient. And so on.

Others are nice-to-haves, but their absence wouldn’t cause much actual technical dysfunction. If Harfbuzz vanished tomorrow, it would result in some ugly text displays. This is not the end of the world.