Exactly. On asymmetrical warfare, one side needs to get lucky all the time while the other only needs to get lucky once.
> Mass-produced drones today are a simple airframe, a lawnmower engine, and the smarts of a cell phone. Ukraine has people making them in basements. Presumably, so does Iran.
Their cheap and simple nature allows them to easily swarm targets and saturate their defenses. You can defend from a dozen incoming drones, but a hundred is significantly more difficult.
Also, consider the massive quadcopter shows in China as an example of how a well placed shipping container can swarm a target and make a devastating attack. Ukraine demonstrated one and disabled a significant part of the Russian bomber fleet.
> Worst outcome is the US attacks Cuba, Cuba allies with Iran, it turns out that Cuba has been stocking up on Iranian drones, and Cuba becomes a forward base for drone and missile attacks on the southern US.
Cuba would be foolish not to do that at the first opportunity, not to attack the US, but to neutralize any offensive from the US. Without a navy, a land invasion, or an effective blockade, is impossible.