Yes, I watched some drone light-show/fireworks displays recently, and thought, 'wait till the drones are the size of flies, these shows will be happening in restaurants, bars, in your living room'. Imagine walking into a room full of fireflies that move around you as you walk, etc.
Bottleneck has been and continues to be energy density. But eventually there will be a breakthrough in battery tech and we will reach new heights of utopia/dystopia.
The drone swarm wars will be crazy. One of the current strategies is to crash your swarm into the enemy swarm and hope you take them all out with what you got