Drones are making the doctrine of boots on he ground somewhat obsolete. Ollie's Army has all the drones you could want...
I don't think it makes them obsolete, it just changes the game.
Small drones let you aim artillery much more effectively and the larger are 100x cheaper than jets for longer range attacks.
Russia can't send jets into Ukraine anymore so Iranian drones were the only option. But it seems either they are running out or Ukraine has figured out how to mostly stop those.