Others have already mentioned how why this is a bad idea (e.g. common plaintext tools don't work, added complexity, etc.)

But I'll also mention that this pretty much already exists. You can have whitespace options for git. I also imagine there's some setup using hooks that uses one formatter locally, and another for remote.

Also, the common IR already exists - it's just the AST. It was "solved" back in the day when people were throwing whatever they could to the wall to see what sticks since it was all so new. With the benfit of hindsight, I think we can say that it's not that good of an idea.