It's part of a rarely-discussed issue with beyond-visual range (BVR) missiles. For all the hype about technology, they have a horrifically low kill rate against live and aware target. If you look at stats against maneuvering opponents actually beyond visual range, ones with the senors to detect the radar-guided missile approaching, the kill rate is on the order of 15%. Doing the math, the fancy new fighters don't have the missile capacity to confidently down any BVR target, hence the need for a "truck".

This article is where those quotes come from:

https://www.flightglobal.com/news/articles/pentagon-touts-lo...

The hard part is developing a strong enough AI to do what they want. Current uncrewed vehicles all have a remote human pilot. Air Force brass wants to do away with that bit. Maybe it's six years out but I would be extremely surprised.