Interesting bit of trivia: the S-matrix concept is also where the so-called S-parameters came from, which are used by RF engineers to describe amplitude and phase relationships at input and output ports [1].

There was some cross-pollination with the physics community in the 1960s that helped the RF people with circuit modeling problems they were facing due to the limitations of existing models. [2] Hewlett-Packard jumped on this with both feet [3], because S-parameters were a natural fit not only for modeling linear devices and circuits, but for measuring them using the vector network analyzers they were developing at the time.




Nice exposition on the physics side; the S-matrix formalism has also played a major role in the mathematical theory of quantum chaos and aspects of representation theory.
Maybe we don’t need a new model, but rather just accepting that the universe can be two seemingly opposite things at the same time

Like the particle/wave duality

Maybe the whole universe is both quantum and not, at the same time. And we just perceive it differently at different scales. Like with a stroboscopic light, we might perceive things differently depending on how we are sampling (and not necessarily because the thing is different)