Couldn't the aeronautical capabilities of an unpiloted aircraft have a significantly higher ceiling if the design doesn't need to accommodate for limiting g-forces on a human?
Not by much. Building airframes that can handle higher G forces than a human comes at a huge weight penalty which impacts cost, range, and payload. Plus, it becomes really tough to avoid compressor stall when the flight envelope gets into high AoA plus high speed. The engineers end up having to do funky things with the inlet that increase drag and radar signature.