This is not so relevant for modern agriculture, but my family still has the Valmet 361D tractor my father bought in 1963. It runs as good as ever. The diesel engine needed to have the cylinder tubes replaced some 30 years ago, and other mechanical parts do wear out and are replaced, but this thing isn't going to be out of use because of software issues.

It's too small to be very useful in modern farming, though.

The only reason why things are scrapped is when the price of repairing starts to exceed the value of the product. In places where labor is cheaper and products are more expensive, you see more of a repair culture. Cars is one of those examples - if you've got some basic repair skills, you can keep a car running for a long time. Getting or making parts can be challenging, but not unsolvable. The problem of course is that a lot of work is done by garages or repairmen, who will charge an hourly rate relative to the standard of living here. or something.

Ergo, if a repair costs $1000 for a car worth $1000 it's not worth it, if that same repair costs just $100 it is.