> Did those people become unemployed?

Either unemployed or forced to work in even less desirable places, yes.

> They mostly stopped working in those fields because everyone hates farming and mining

https://en.wikipedia.org/wiki/1984%E2%80%931985_United_Kingd...

No matter how hard the work conditions are, people don't usually accept its disappearance.

Automatization reducing work can actually be a good thing, as it is the reason why we can have vacations, retirement and long studies: because the society's need for work is lower than before.