Current advancements already allow tractors to go autonomously go over the bulk of the same large areas of ground that they have for the past decade (already logged and recorded), graceful fallback alerts remote farmer to make a human decision re: tree falls, new rocks, unexpected gear state changes.

These are useful advancements in machine control.

These developments have locally run in parallel with the above linked Rio Tinto work here in W.Australia - it's a pity the largest mining operation on the globe has imagined its work to be productive and useful and allowed its cost analysis to sway its thinking lacking your insight to the contrary.

I work for John Deere, I can't speak for the company.