The more fingers you can wrap around a release handle, the more you can distribute the pressure of the draw weight.
However, you also have the potential to apply inconsistent pressure from each finger to the handle and either affect the angle of the release when you anchor, or during the shot process.
You give up some control and leverage when you use a release with fewer than 4 fingers, but the benefit is it is easier to be consistent. You basically have fewer ways to affect the angle of the release at full draw or fewer points of pressure to affect the shot process.
That's why 2-finger releases are popular with some, but I think 3-Fingers are a good balance.