First Aspect
Guru
This is technobabble. Spectroscopy is the study of quantum transitions.Spectroscopy is the measurement of the energy or power distribution in a frequency range, that's most definitely physics, that you guys can assign certain features of that distribution to changes in configuration of a group of atoms (or subatomic particles) is taxonomy of the spectra.
The point you are missing is the true Venn diagram of "chemistry" and "physics" overlaps. Chemists need to get a lot more into the fundamentals that you think in order to do meaningful chemistry.
If your idea of chemistry is more polystyrene balls and plastic straws, then sure, you are right. Organic chemists by and large get away with albeit fiendishly complex application of 19th century approximations, with more exceptions than there are rules. We thank them for their efforts.
You might even argue that chemistry came first by the way, when philosophers were striving to identify the essential elements. They got it totally wrong, but they were only philosophers. The early chemists needed to study the physical nature of matter a bit more to make sense of it, and some people just go down that rabbit hole entirely.