It's likely not even that. According to Jacek Bartosiak, Polish geopolitics popularisator, it came by a kind of blind "luck".
He travels a lot to Ukraine and talks a lot with military and dual use manufacturers.
Regular arms manufacturing in Ukraine was, just like anywhere else, not very innovative and dominated by big actors that could make sure nobody else can enter the market.
But the drones were not seen by them as anything serious, and due to dire needs the market has been deregulated, which allowed many small businesses to flourish and develop the fantastic industry that Ukraine is so proud of now.
But that came mostly because the big fish let the small underdogs on the market because they thought there is no market.
Hope I'm not mixing anything up.