Waterpump bearings can fail pre-maturely if the belt tension is too high. Water pump seals have spring loaded lips but they have limitations if the sealing shaft is off center from the excessive load. It can cause wear on the high contact zone and partially unload the opposite side. If there are abrasives in the water, they can accelerate the wear as well. My 2GM20 has over 2,000 hrs on the original waterpump, fresh water usage only.
Cal 9.2 #19 SilverSwan