Uh, MacOS has zsh (which has far more features than most other POSIX shells), and even old bash has POSIX compatibility.

Your TV/IoT device likely has busybox, as does your router.

You install git on windows, it's got a (POSIX) shell.

The number of places that lack a shell is tiny.

Node/deno/bun are rare, and browsers whilst being more common, still require the device to have some kind of GUI.