When we were doing our pre-war certification for desert combat, we had a chance to train right next to an anti-aircraft battery. We wanted to know the detectability of the Shadow at mission altitude so we could adjust things to keep from getting shot down. For those that don't know, the Shadow 200 (RQ-7A, now superseded by a bigger model), is built out of a carbon fiber composite with radar absorbing paint. The engine vents exhaust to the top backwards directly into the propellor, which does a wonderful job of breaking up the heat signature. It is approximately 11'x13'. Anyways the shadow is small and was meant to have a very low detectability factor. After the AV is a few thousand feet above the ground, you can either see nor hear it. Our own patriot anti aircraft battery was unable to detect it at mission altitude without setting their gear's sensitivity up night enough to detect large birds, which is totally impractical.
So was the Shadow built to be stealth like a B2 or F117? Nope. Is it effectively stealth when flying missions at several thousand feet above the ground? Yup! Go the the Wikipedia page for "Ground Control Station" which has a picture of me in the back of a Shadow GCS sometime around 2001.
Now the bigger stuff such as the predator / reaper / global hawk? They have much larger cross signatures, but they are more capable platforms. The shadow only had an approximately 6-7 hour in-air endurance.
"In addition, a new generation of low cost, reusable, and ultimately disposable UNMANNED [emphasis added] systems can help invert the cost imposition of A2/AD networks by overwhelming an enemy’s ability to engage at favorable cost exchanges."
I'm curious as to whether you can conceivably build effective aerial platforms for cheaper than you can build missiles to knock them down, but I'd imagine you could do so with decoy drones.
I believe the unmanned part is key for enabling this -- hopefully no one would have ever suggested fielding survivability-inferior but numerically-superior manned force as a viable strategic aim...
Every wartime opponent of the USA for the last half century that we've lost to, has eventually won using that exact strategy. Its kind of expensive, but everyone who tries it, beats us eventually.
Everyone always thinks about the consequences of the above as 5 Shermans (or T-34s) vs. 1 Tiger. But the more important distinction was likely 2 Shermans + infantry vs. 0 Panthers + infantry.
From my very casual outsider view, it looks like manned platforms are indeed becoming more expensive, but unmanned platforms are much cheaper and taking over much of the work.