I suspect it has to do with western military industry shifting towards premium low volume products since the end of the last war, perhaps because making weapons

I suspect it has to do with western military industry shifting towards premium low volume products since the end of the last war, perhaps because making weapons of war had been weird to some people lately. They don't make hand portable or vehicle mountable 7.62mm or .50cal or 14.5mm mini-CIWS, only the multi-trailer ship-sized versions that are total overkill for drones.