Show us one example where shutting down a company increased competition among the remaining companies. That's just not something that happens.
Smaller companies compete by building products that are better than the current market leaders. If the market leader disappears, they no longer have that incentive, as people are going to buy their products even if they don't improve them in any way, since the customers don't have a choice.
I'm not saying there won't be drones any more. I'm saying that they won't be competitive with DJI in terms of quality or value of money because they don't need to be.