I think its possible that some people commenting are missing the larger point (and I think this widely distributed article misses it as well). The problem isn't the size of the tractor, or the farm or ranch or the amount of money the "farmer" makes, and it's not just that older tractors (of any size) are simpler, more repairable, and less reliant on complex systems... it's that John Deere is heavily opposed to "Right to Repair". They're system and engine software is completely locked down, no one other than a dealer can access it, change it, manipulate it any way. (Nevermind that their parts are often proprietary... and have no third party option.)
The modern John Deere company believes when you purchase a tractor, you don't purchase an item or a machine, you buy a right to use their device.
This approach to business didn't work for Apple (they now authorize repair and distribute parts to non-Apple repair shops) and I think most of us hope it won't work for tractor manufacturers.
BTW, I'm not sure Kubota doesn't have a similar POV regarding right to repair. I'm not sure their systems aren't just as locked down, but they're not as big or powerful as JD.