I didn't say they were created by new farming techniques, I said new jobs in general were created by increased urbanization, which was partially fed by agricultural innovations over time. For example, Jethro Tull's seed drill (1701) enabled sowing seeds in neat rows, which eliminated the jobs of "broadcast seeders" (actual title). If you lost your farming job due to automation, you could move to the city to feed your family.
There is no similar net creation of jobs for society if jobs are eliminated by AI, and it's even worse than that because many of the jobs are specialized, high-skill positions that can't be transferred to other careers easily. It goes without saying that it also includes millions of low-skill jobs like cashiers, stockers, data entry, CS reps, etc. Generally people who are already struggling to get enough hours and feed their families as it is.