Why does electrode potential depend upon enthalpy of hydration and sublimation?
In a thought experiment, you can substitute the electrochemical half reaction by three steps:


Removing atoms from the electrode into the gas phase (sublimation)
Removing electrons from the atoms (ionization)
Solvating the resulting ions


If you have quantitative descriptions of these processes, you get a quantitative description of what is actually going on. This is because many thermodynamic functions (such a enthalpy) are functions of state, i.e. they don't depend on the path from A to B, just on the state of A and B.

I would have said these quantities are related rather than one depends on the other. There is really no causality here.