I think self driving cars and carts will also kill almost all middlemen. Why go shopping for food if you can get everything shipped to your fridge for 20-30% less, direct from the producer. Google will probably also offer to drive you for free to a medical specialist and start doing tests after you entered the car. So we probably need a lot less physicians too.
I'd argue that we'd probably need a lot more. Diagnoses would be more accurate so people would be inclined to use the health system more. Health work would be cheaper because the expensive doctor component would be used less. Time to go to the doctor could be more efficient (still working through the car ride) so people are even more likely to go. Overall that could likely mean higher demand for healthcare, including the human component.
Your food shopping point still needs middlemen. You have "chain of trust" issues with the producers. How do you know that you'll get good oranges from the orange grove. Who capitalizes the distribution system and designs the business model.
Considering historical examples, we'll see more use for people in the economic problems that are still machine hard. Machine easy economic problems will converge to resource costs + any premium for monopoly. This will free up more demand for other products. People still want to buy an easier, better life.
There are often 3+ intermediaries between many farm products and the consumer. Dropping that to 1 chould be a huge change. Cow, wholesale, bottler, distributer, store, you. Granted, there is a lot of variety in this as some farms do there own botteling etc, but some products pass through even more hoops.
