In most conditions, light doesn’t interact photon-to-photon. The field they flow in doesn’t engage the constituent particles this way. Photons are massless electro-magnetic force carriers for matter. If you have a million photons going around, they don’t care about each other directly, unless confined and given time to engage each other (which is a bizarre physical existence, such as in places we can never observe; namely, high mass stars and black holes). In this sense, we can say photons don’t occupy the same space or energy state … If photons land on an atom’s electrons, then they start doing things that could be overall viewed as interfering, but really it’s just an indirect effect. Photons can get matter to reverberate via it’s orbiting electrons to give an illusion of interference. This so called “interference” is a state of the electron(s)’ reaction to the photon. So, photons interfere with each other indirectly through matter, but not within the EM field they exist in unless in extreme (highly rare and misunderstood) states. The greater interference is just observational inaccuracy of what appears to be interference. Nothing interferes usually; it just becomes so chaotic we see jumbles due to our observational limits (physiological and engineering/analytical limits).
Photons are odd. They are beyond understanding. They are going the fastest possible (they’re unimpeded by cosmological speed-limits), they’re massless (unimpeded by energy/matter laws), and beyond physical time too (the lack of the previous two grant this). Yet, they ferociously engage matter and it’s force carriers; just to continue their massless madness through matter-induced space-time curvature.
To round it off, light doesn’t interfere with light on it’s own. But, it’s interaction with atom’s structure can cause observable patterns worthy of the label, “interference”. Anomalies allow photon-photon combination, but normality allows kinetic interference of matter states via photon effect.