Because there is no technological alternative (e.g. strawberries, safran), or some quality standards require hand-picking (e.g. grapes)
Oops I specifically had wheat in mind when writing the stuff about farming. You are right that there’s lots of stuff this doesn’t hold form.
As for “machines drive themselves nowaday”, even if by “people” you mean “US farmers”, I don’t think this is true. It is true that some such machines exist, especially for the farming of wheat and corn, but they aren’t as widely used (yet) as you suggest.
Oops I specifically had wheat in mind when writing the stuff about farming. You are right that there’s lots of stuff this doesn’t hold form.
I see, thanks.