If only. Dirac and Wiener did not understand the significance of the action appearing where it did. Feynman gave it meaning. An analogy for what you are sayin

If only. Dirac and Wiener did not understand the significance of the action appearing where it did. Feynman gave it meaning. An analogy for what you are saying is that Einstein just rederived Lorentz’s equations. That’s one of the most interesting characteristics of physics, it’s not just math and computation, meaning is hugely significant. I’d also say the path integral is not what he is most known for among practicing physicists, but that’s another story (I recommend “QED and the Men Who Made It: Dyson, Feynman, Schwinger, and Tomonaga@).