[kubanczyk]

Spot on. It seems that OP is considering (1) a rewrite that can entirely fit into the mind of an engineerXYZ, and also (2) will be led by the same engineerXYZ, through executive empowerment.

I guess that in your case probably (1) did not hold. Or maybe (2) did not hold, or both.

OP's experiment doesn't prove at all, that an entire org can rewrite a complex app where 1&2 do not hold. Every indication we have is that org's executive functions perform abysmally for code writing (and rewriting). So exactly the point you are making. It would obviously mean that there is value in code, along the value in the org, once we get above the level of the value that conceptually fits into 1 head.