Let’s say that all of the ambiguities are automatically resolved in a reasonable way.

This is still not enough to let 2 different computers running two different LLMs to produce compatible code right? And no guarantee of compatibility as you refine it more etc. And if you get into the business of specifying the format/protocol, suddenly you have made it much less concise.

So as long as you run the prompt exactly once, it will work, but not necessarily the second time in a compatible way.

Does it need to result in compatible code if run by 2 different LLM's? No one complains that Dropbox and Google Drive are incompatible. It would be nice if they were but it hasn't stopped either of them from having lots of use.

The analogy doesn’t hold. If the entire representation of the “code” is the natural language description, then the ambiguity in the specification will lead to incompatibility in the output between executions. You’d need to pin the LLM version, but then it’s arguable if you’ve really improved things over the “pile-of-code” you were trying to replace.

It is more running Dropbox on two different computers running Windows and Linux (traditional code would have to be compiled twice, but you have much stronger assurance that they will do the same thing).

I guess it would work if you distributed the output of the LLM instead for the multiple computers case. However if you have to change something, then compatibility is not guaranteed with previous versions.

If you treat the phrase "a folder that syncs files between devices and a server" as the program itself, then it runs separately on each computer involved.

More compact, but also more ambiguous. I suspect an exact specification what Dropbox does in natural language will not be substantially more compact compared to the code.

"syncs" can mean so many different things

You just cut out half the sentence and responded to one part. Your description is neither well defined nor us it unambiguous.

You can't just pick a singular word out of an argument and argue about that. The argument has a substance, and the substance is not "shorter is better".

What do you mean by "sync"? What happens with conflicts, does the most recent version always win? What is "recent" when clock skew, dst changes, or just flat out incorrect clocks exist? Do you want to track changes to be able to go back to previous versions? At what level of granularity?

I’ll bet my entire net worth that you can’t get an LLM exactly recreate Dropbox from this mescription alone.