This is the old idea of giving two teams the same project and letting a third team judge/merge a solution incorporating good parts of each. Just like the old idea, of course you would do this with infinite resources.

You can already sort of do this in way that isn't insanely wasteful if your project has strong measures of correctness. But even then things like compilers have a very real axis for friction in "user/developer/agent experience".. doing it at scale involves some kind of LLM-as-Judge pointed at something which is not an objective value. So .. not only piling on additional false work, but work which is very likely to be incorrect/noisy.