The classical electromagnetic field is emergent from an enormous number of photons, and that can be proven mathematically.
Experimentally the simplest demonstration is the emergence of the double slit interference pattern one photon at a time:
Single-photon camera recording of photons from a double slit illuminated by very weak laser light. Left to right: single frame, superposition of 200, 1’000, and 500’000 frames.
One sees the individual photon leaving a footprint that looks random, but is not as the phases of the photon wavefunctions in superposition build up the classical interference. One uses this sequence to stress the quantum mechanical, probabilistic wave nature of the photon wavefunction
This pattern is explained by both QED and classical electromagnetism.
Yes, Maxwell's equations for light are very useful and it is not necessary to go to the underlying quantum level, because the mathematics is consistent. Only for absorption and emission spectra the existence of photons is absolutely necessary, and the photoelectric and black body radiation of course.
As far as semi classical claims go, the "semi" is indicative of phenomenology fits, which is fine for fitting data, but not an argument against the underlying quantization.