We live in open societies. Attacks can come feom anywhere. For all we know, there are warehouses somewhee near cities and strategic targets, just full of drones waiting to be launched. You don’t need 800mi range to attack America. You just need to walk a few hundred operatives across a big open border, then have them use commercially available hardware to build drones. I’ve got several myself I built from parts.
Why have any military when you have nukes? Because launching a nuke takes war to a whole nuther level, and because if you use nukes to threaten people, eventually your bluff will be called and you either start a nuclear war or lose.
Drones are precision attack weapons. They are used surgically. Nukes are blunt insteuments you use as a very last resort when all else is lost.