Weird low poly shadows

I have a problem with my shadows and i can’t figure out what’s the problem here. It looks completely fine in Substance and UE and even in Sketchfab the same topology looks fine on top but on the sides it gets weird like it’s shadowing based on lowpoly instead of bake.

As i understand the problem comes from the way i’ve tried to reduce the amount of horizontal loops but i mean i already did that before and it looked completely fine.

In one thread i saw that there can be problems because of the wrong winding but i checked in maya and it says winding is the same for all faces, at least if i understand it right.

So i’ve played around with “Shadow Bias” and seems like it fixed the problem. I guess my question now is “what is this shadow bias”? So i guess the lower the value is the more shadows try to align with actual geo. What’s on the opposite side of the spectrum then? I don’t really get the principle here.