This argument is based on the notion of proof irrelevance – if a theorem is true, any proof is as good as any other. This is not the case for computer programs – two programs that implement the same specification may be very different in terms of performance, size, UI/UX, code maintainability, etc.
Performance and size can easily be added to any specification, maintainability is not a problem if you never have to maintain it, UI/UX are design issues not code issues. If you specify a UI, it will have the UX you want. We can already do UI creation with visual editors.
