i shoot on the widest aperture most of the time for the first few years of my journey but because my camera at that time is only m43 sensor and most of m43 native prime lens is consider sharp at the widest aperture (f1.7/f1.8), so i didn't notice the lack of sharpness. I also want to max out IQ(lowest ISO possible) from that small m43 sensor so shooting at the widest helps.

Now for m43,
i am usually at F4 and above for studio type of shot(with help of flash) where i want deeper DOF or sharpness from the lens
F5.6 and above for landscape/scenery type
F1.8/F2.8 (widest available) when low light where I don't care about sharpness at all, just want max IQ from my camera or action type since more concerned about the max shutter speed I could use before the IQ falls apart

for apsc, FF, generally i just add another 1 or 2 F-stop from my m43 practice