https://en.wikipedia.org/wiki/Unmanned_aerial_vehicle: “An unmanned aerial vehicle (UAV) or unmanned aircraft system (UAS), commonly known as an aerial drone or simply drone”
⇒ “Drone” is orthogonal to size or shape. It is possible to design an unmanned aircraft that can (largely) replaced manned fighters or bombers.
And that isn’t hypothetical. See for example https://en.wikipedia.org/wiki/Manned-unmanned_teaming, https://www.lockheedmartin.com/en-us/products/s-70uas-u-hawk...