With modern cameras bias and flats are all you need. Bias is trivial, flats are relatively easy.
@WadeH237 has already indicated that darks will help. You can skip them but the result will be less good. My cooled IMX571 sensor camera (one of best modern sensors on the market) is clearly suffering from hot pixels so skipping darks in the processing would be ill advised strategy.
Secondly frames will suffer from unequal dark current so the measured pedestal will differ for each pixel. The only way to get it removed from a light is applying a master-dark. The temperature of the dark should be the same as the light. If the dark temperature is lower or higher then the light you get worse results. I have measured the effect and reported it. Link will follow.
Thirdly without applying darks the flats will overcompensate the flux drop in the corners of the lights. So the flat will not work properly as desired.
Replacing flat darks by bias frames for no reason would be a risky strategy. It doesn't take more time to make flat-darks then bias frames. But flat-darks guarantees you will compensate for a possibly non-linear behavior of CMOS sensors in the first second(s). So my advice for calibration is to use :
Darks, plenty at the same exposure time and temperature as the light frames.
Flats, using a light source which colour is reasonable white.
Flat-darks at same exposure time and temperature as the flat frames