A drone can't enforce curfew on the streets, and a high tech fighter aircraft can't stop and search a car for contraband, a heavy tank can't knock down a door at 1am and arrest a family and a guided missile can't do a show of force and intimidation by standing on a street corner.
This takes boots on the ground. Security forces who need to eat, rest, recreate, have parents, partners and children. All things which are vulnerable to irregulars with small arms.
See, your mistake is thinking the 2A protects the US by the citizens with small arms being able to fight a pitched military campaign maneuvering against a modern combined arms force.
Its about ensuring that any attempt at a tyrannical take over will be an impossible, bloody struggle rendering the United States weakened and dysfunctional - an unattractive prospect for any home grown tyrant.
Your ignorance of the concept of deterrence is cute though.