In a weird way it kinda reminds me of `exec` in sh (which replaces the current process instead of creating a child process). Practically, there's little difference between these two scripts:
#!/bin/sh
foo
bar
vs
#!/bin/sh
foo
exec bar
And you could perhaps imagine a shell that does "tail process elimination" to automatically perform the latter when you write the former.
But the distinction can be important due to a variety of side effects and if you could only achieve it through carefully following a pattern that the shell might or might not recognize, that would be very limiting.
this is pretty much exactly how my "forth" handles tail call elimination, and it's the main thing that's added the quotes so far since it shifts the mental burden to being aware of this when writing code to manipulate the return stack.
as you imply towards the end, i'm not confident this is a trick you can get away with as easily without the constraints of concatenative programming to railroad you into it being an easily recognizable pattern for both the human and the interpreter.
But the distinction can be important due to a variety of side effects and if you could only achieve it through carefully following a pattern that the shell might or might not recognize, that would be very limiting.