Calculate transfer function H(w) of Schmitt trigger with RC at inverting input
As already told by others, its not useful to apply linear frequency analysis to this, heavily non-linear circuit. Do time domain simulations with different input signals to see the behaviour.

A qualitative analysis of one, probably interesting case:

If the time constant R2 * C1 is so long that it virtually kills all variation of the Vin, you have only the average Vin at he inverting input of the opamp. This can make the circuit useful as a level detector with self-adjusting treshold.

If Vin has long periods of "no change" and the idle Vin is far from the average Vin of the active periods, you get errors when the changes start, because there's wrong average in C1.

BTW. Your Rf and R1 give only about 3uV hysteresis. I bet it's useless for anything practical. You should have bigger R1 or smaller Rf or both. The hysteresis = (R1/Rf)*Output peak to peak swing.