Frankly, there is no more lift or thrust in 5 vs 4 or 3 blades, as long as the total solidity of the rotor (total blade area divided by the total disk area) is the same. In other words, 4 skinny blades have no more lift than 3 somewhat wider blades. More blades usually weigh more, so that for the same solidity, a greater number of blades can reduce payload a bit, but the vibration is a bit smoother (especially when going from 2 to 3) with more blades.