The presence of a human pilot isn't quite a limiting factor in the way most people think. Building an aircraft to structurally support high G loading is difficult, and prone to compounding challenges. The smaller and lighter an aircraft is, the easier it is to make it capable of high Gs. As the aircraft gets larger and heavier, the structural support needed for high Gs gets heavier, the heavier something is the more strain it is placed under at higher Gs. This means that the larger a plane gets, G loading becomes exponentially more difficult to increase. Airliners aren't rated to 9G just because most passengers would hate it, building an airliner to that structural limit would be massively difficult.

High G loads also contribute to structural fatigue over time, leading to lower design limits in aircraft that are intended to have a long service life. Many modern fighters are actually rated to G loads below their structural limits specifically to increase airframe lifetime.

This is why unmanned aircraft capable of extremely high Gs tend to be small, light, and intended for either single use or limited use. Adding a pilot to an aircraft doesn't reduce its likey maximum G loading just because of the need to accommodate the squishy human. It means the aircraft must be at least a certain size and weight, and it also means the aircraft is something that will need to survive and be reused, likely for a very long time.

Things like OWA drones and missiles can have very high G limits because they are relatively small and light and there's no worry about structural fatigue since they only need to survive a single trip one way. Fighter sized combat drones like the currently in development CCAs are likely to have very similar maximum G loads to manned fighters because they will be similar in size and will want to be reused for years of service.