that's a good one thanks! One aspect which does not fit too much it the fact that the farmer cuts the plants to eat them and the rancher kills the animals. Uber or Airbnb don't kill the users, they keep them alive and extract a part of the value created.

I think I got it thanks to you tough: milking cows.

Does it work? Too harsh?

There's also orchards, and beekeeping, raising chickens for eggs might qualify.

As well as this: https://en.wikipedia.org/wiki/Aphid#Ant_mutualism