I wouldn't. That's why farming equipment used to be modularized - the drive unit would be in constant use around the farm, the add-ons were job-specific. With more expensive and infrequently-used equipment, someone would buy one and then lend it out to everyone in the village in turn, or offer using it as a service.
If manufacturers want to step into that last line of business, well, that's a separate topic from right-of-repair, and mostly boiling down to how much are we willing to allow a corporation to tax users after the fact. Me owning and lending out a repairable, DRM-free harvester combine, vs. me lending out a DRMed combine, vs. manufacturer lending their combines directly to users differ primarily in the amount of operational money that goes to the manufacturer instead of staying within the local economy.
(That, and the amount of money farmers have to pay in total. I can harvest your field for the price of a crate of beer and you welding a fence for my chickens. John Deere will only accept hard currency.)
Regardless, keeping machines unrepairable is only adding inefficiency to the process - for which, as far as I'm aware, the manufacturer does not pay. If they want to provide "tractors as a service", perhaps they should be forced to go all in, and provide SLAs. When they're facing a choice between spending $100k to parachute a technician into the middle of nowhere, or spending $100k to reimburse for a lost harvest, perhaps they'll be more receptive to the idea of letting people repair their own things.
(That, or Zipline will start getting inquiries about flying tractor parts back and forth via drones.)
So ultimately the farmer will be paying for it.
Because you want to invest in your business? So that, once it's paid off, you can stop giving part of your profits to someone else? You know, the old 7-year-payoff rule of thumb? That old chestnut?
This is the problem with most industries in our over-capitalized system now. In every sector, large companies are trying to monopolize at least a horizontal -- if not an entire segment -- so that they can extract rent from the market forever. The very notion that people are allowed to own things, and not pay service fees till the end of their life, is utterly vanishing, from huge farm machinery to freaking light bulbs. Letting companies permanently insert themselves into our daily use of their products is a total change of mindset, and one which people over 40 will probably never be comfortable with.
There's something fundamentally opposed to the idea of a free society when you have a dozen companies requiring constant access to your homes and appliances and cars and personal electronics at all times, in order to keep them running in any useful way. Beyond simple monopolization, every company is doing it. This is quickly leading to an almost collusive situation where there are entire product categories are becoming exclusively IoT devices, with soon-to-follow subscription fees, and there will be no other practical alternatives.
That is a factor, but there are counters. You miss out on whatever advances next year's model has. The machine won't last forever, so even after it is paid off you only get a few years before you have to buy a new one (or put major rework into the old one - often this isn't worth the labor costs since you don't get the scale of an assembly line)
In the end each farmer has to make their own decision. Some will buy the equipment, some will lease it, and some will hire someone else to do that work. There are trade offs. Many accountants have run numbers and discovered that the obvious choice is the worst possible one, but this is a case by case analysis.
I get that you want to say "it depends," but the original context is a TRACTOR. Something that, historically, can easily last 20 years, if not 50.
This is also what makes withholding a repair key so pernicious, as they have you over a barrel, since your productive window with the equipment is also limited.
Not all machinery is equally shareable, though. I think for a combined harvester there are two challenges:
(a) Can you move them around the world easily enough so that the costs actually can be shared by multiple users? Or will the payback period just become super long and everyone is happy with that?
(b) From a policy maker perspective, do you want to rely on a supply chain for the full equipment on critical food infrastructure? What if all the harvesters are stuck in some channel?