Why is the fine structure constant a combo of those three quantities you might inquire? Electric charge, as I postulated in my thread The Double-slit Experiment and Quantum Consciousness, is the signature of nonlocal entanglement within the atomic and subgravitational scale, electromagnetism's synchronicity quantity as demonstrated by a simple magnet and elsewhere. Planck's constant is the smallest known amount by which electromagnetic matter can be quantized, consisting in the lower limit of its locality. And light bosons saturate this atomic realm, binding its elements within electromagnetic fields, similar to how gluons weld together the nucleus, so that the speed of light is the core causal velocity of change amongst atoms, with apparent instantaneity taking effect more substantially at the gravitational scale and subatomic scale that ensconce it (and which relatedly involve larger energy differentials as described in my thread Do Physics Equations Disprove the Speed of Light as a Constant?)

Electric charge is the nonlocal pole of the electromagnetic scale's causal spectrum, Planck's constant the opposite local pole, and light speed the core mediating factor in its fluctuations. Each atomic orbital's behavior is simultaneously parameterized by these three flux constraints, the maximally nonlocal, maximally local, and radiative. An orbital, as the core unit of chemical divisibility amongst atoms, shows up in various calculations as the fundamental entity within which nonlocality, radiativity and locality in electromagnetism synthetically take effect. The fine structure constant is like multiplying by 1 orbital, the base unit, and 1 orbital is approximately 1/137th of an atom.