I have authored a shell in Go and while it doesn’t aim to replace coreutils, it does have a decent number of builtins as part of its application.

So in theory I could build a feature that allows you to ship a self contained executable like you’ve described.

If this is something you’re genuinely interested in and my shell has the right kind of ergonomics for you, then feel free to leave a feature request:

https://github.com/lmorg/murex

you can write bash but run the scripts on systems that may not have bash, is my first thought. packaging “shell” scripts into a scratch container or similar sounds pretty nice for certain use cases.