Part of a broader pattern in military technology right now. All weapon systems that consist of an expensive vehicle and an expensive-to-train crew are being re-evaluated against drones right now. If you're fighting a highly asymmetric conflict where your enemies can barely touch your expensive toys then it's less of a concern. If you're fighting near-peer it's a different story.
Efficiency starts to matter in a near-peer conflict.
I prefer the Culture term “equiv-tech”