Keep in mind that tractors are also getting massive.
The economics of row-crop agriculture is "you gotta farm more land". That means spending as much time in the field as you can with as big a machine as you can.
So not only is time you spend fixing your tractor yourself time you're not spending on your primary job, it's also working on a machine that's just monstrously huge. Delegating that work to a specialist with specialized tools is a very reasonable way to live.
Exactly! The old image of a guy on a Deere 4020 pulling an eight row implement is just unsustainable in today's agricultural system. Whether that system is sustainable is a different question.
The issue is that the specialized employees is not someone you hire on payroll who has access to tools you purchase. They must be a John Deere employee who comes from out of state and costs you $$$$$$ to calibrate a sensor that could just be a simple menu button and a 20 second wait