[Someone]

…and by the time that software is so bulletproof, this technology will be 30 years old, too.

That is a bit of an exaggeration, but with modern designs, you need wind tunnel data, you have to program a simulator, so that you can test control software without crashing a zillion expensive hardware systems, you need ejection seats and an array of test pilots trained in a flight simulator that behaves exactly like the hardware is thought to behave, etc.

The advantage here is that you could program the software so that it always stays far, far away from danger zones. With fighter aircraft, that is not an option. However, if you do that, the thing will not sell.

[saulrh]

True, but this is also several orders of magnitude simpler than a modern combat aircraft. It has vastly simpler dynamics, it doesn't have to deal with control surfaces, it doesn't have to be stable with irregular patches of supersonic flow on its wings, and so on. It'll probably only take three or six years, I bet.