Not sure whjy they never upgraded those bearings, but might be a good time to get an aftermarket if things are chewed up too bad. Taper bearing about bullet proof, but a dual row carrier are also a huge improvement.
Also a good reason not to get carried away with the pressure washer, those seals are no match for 1000psi plus.
"A dead thing can go with the stream, but only a living thing can go against it." G. K. Chesterton