It’s not obsolete. In a country where your military is farm boys, the important thing is being able to start the war. Eventually chunks of the military will defect. We saw this happen during the Bangladesh independence movement. The revolutionaries got lucky and knocked over a weapons depot early in the conflict. They started fighting and a large number of the Pakistani army that was of Bangladeshi ancestry defected. I am confident the same thing would happen if the government in DC tried to oppress Iowa or Texas.

Drones cut both ways. You’re correct that it allows a small number of people loyal to the regime to asymmetrically oppress a large population. But drone technology is in theory accessible to the populace in an industrialized country.