It could also be that we simply don’t understand something about light phase, and that’s causing us to get confused about superpositions. After all, the experiments aren’t on single photons, they are on beams of photons.

Not sure if we're confusing threads here - double slit experiments have been run on single photons and the results are pretty conclusive. Even a single photon is a wave that interferes with itself.

I would expect similar here. Intuition is terrible at understanding what is going on at the atomic and smaller level, or anywhere relativistic anything is happening.

Not confusing threads; the double slit experiment is often given as evidence of superposition. My attempts at replicating the experiment myself have been foiled because it inevitably goes to phase calculations on lasers, which I don't have any idea how to do. I keep looking for a way to do this famous and supposedly simple experiment, but haven't found a way yet. In any case, when I go deep on what is there (as a layman) it inevitably seems to result in phase measurements as the smoking gun proving superpositions exist at all.