Early 1980’s, we switched to a plastic tub from the epoxy coated steel in 1984. The plastic tubs last forever, never rust out.
The new dishwashers only get .8 gallons per fill because of federal regulations and will not wash dishes.
I don’t like most of the new dishwashers at all. Might as well just buy the cheapest one you can find. The drawer type dishwashers are nice, but they cost too much.