Automation and technology in general have made it possible to do more farming with fewer people: https://www.gilderlehrman.org/history-resources/teacher-reso... . In the US job market, agriculture accounted for 51% of workers in 1880 and less than 3% in 1980. It now appears to be closer to 1% depending on which source you reference.

Hard to imagine many occupations that have undergone more radical change in the recent past than farming. The profession is now utterly technology-dependent, and a few companies like John Deere have hastened to take unfair advantage of that. Hence the growing advocacy of right-to-repair laws.