The concept of autonomous machines is a fad?
As technology advances, autonomous machines may very likely grow beyond the definition/parlance of a "drone" (machinery designed and dedicated only to perform specific tasks) into more powerful forms of intelligence.
At that point, such machinery graduates beyond the definition of an artifact (a possession held in the ownership of higher-order life), and one might speculate whether it represents a form of life unto itself, or where one might draw such a boundary.
Either way, such sentient machinery (read: not drones) might not be bound by geological/astronomical timescales, outlasting its inventors possibly permanently, but still represents a component of the Fermi Paradox. If such things are possible, where are they?
Yeah, you're just making shit up. The first machine intelligence in pop culture can be found in https://en.m.wikipedia.org/wiki/R.U.R. (the origin of the phrase "robot"). Non-sentient autonomous machines are even older. https://en.m.wikipedia.org/wiki/Golem Sci-fi authors have been talking about modern-looking self-replicating machines for decades.
Maybe you have some weird definition of a drone? Drones in common parlance have come to be associated with any robotic vehicle, and are used in technical parlance to refer to a huge variety of autonomous or semi-autonomous machines.
Please don't create accounts to break the HN guidelines with.