Four parts that the slurry eats
Inside, a slurry pump relies on four parts, and all four get eaten.
The impeller drives the slurry. The volute takes the impact. The throatbush and the rear liner close the impeller from the front and back.
The casing lasts for years, and the wet end is replaced as a set. A good mechanic keeps not a second pump in stock, but a second wet end.
The Europeans left, the pumps stayed. Chinese factories have long cast wet ends to the same dimensions in high-chrome iron.