Well, one would say that's the beauty of it. What is AI? Basically code lines on a computer (oversimplification, but still). Much easier to buy, steal or be given lines on a computer rather than a very visible, materially, politically and otherwise, combat aircraft or indeed any other highly visible combat system. DPRK would not need a western style CCA with very intricate requirements, programming, connectivity with other systems etc, just one tailored on their needs, get up, point that way, shoot, get back (if possible). Again might be oversimplification, but still it's easier to focus on achieving a narrow set of operational capabilities tailored to DPRK needs/airspace, rather than the all encompassing western approach/needs.