There is no specific reason for a program that uses the XDG dirs on other unices to not use them on macOS, other than some idea that it's "alien". You can have

There is no specific reason for a program that uses the XDG dirs on other unices to not use them on macOS, other than some idea that it's "alien". You can have ~/.config/. Nothing in macOS prevents you from having it. And so, some programs do. The worst thing that happens is that, instead of having one directoy ~/.foo you now have one directory ~/.config/foo and nothing else in ~/.config. But as soon as you add the second thing that uses ~/.config, you now have two directories in there instead of a second dotdirectory in ~. It's just that for a bunch of them the XDG path is only used if it exists - e.g. emacs predates the spec, so it uses ~/.emacs.d (and a few others) first. Cargo doesn't use the XDG paths at all, apparently - https://github.com/rust-lang/cargo/issues/1734 https://github.com/rust-lang/cargo/issues/1734. However it also needs a directory for binaries (~/.cargo/bin) and ~/.local/bin isn't actually in the spec at the moment (https://gitlab.freedesktop.org/xdg/xdg-specs/-/issues/14 https://gitlab.freedesktop.org/xdg/xdg-specs/-/issues/14).