In some sense military technology is like an ant and consumer technology is like a 100 foot high giant robot. Military technology will produce innovation in wartime but in peacetime it is a backwater.
I guess the keyword here is "seem", we don't actually know, and it'd probably take 20+ years before anyone would know. Most people didn't know about lots of military technology until it's basically mainstream on the entire planet, so you're right now (potentially) in the moment where that stuff is happening, we just don't know about it.
I wouldn't characterize it so uncharitably. We need this military technology and if we aren't getting the funding or efficiency we need from the government and private companies see the need (and there is a need) then this is just an example of the dynamism of our economy working well. In some other countries when such a conundrum arises they can't response - reliant only on the government to put together some big program that doesn't go anywhere and can't pay high enough salaries to attract talented people to make it work.
- They don't want the enemy to also have the technology.
- They don't want the enemy to be able to plan against surprise weapons.
So, for example, if Ukraine developed a robot that looked like a wild animal, could conceal a bomb, and then walk across the border and explode at a target, they wouldn't want Russia to know. They would keep it super-secret and keep exploiting it until Russia figured out how to monitor the border for robotic animals.
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This isn't a conspiracy; it's something you can learn about by studying WWII tech development. The Nazi enigma machine is a great example: The Nazis kept it secret, and the computers that the Allies built to break the codes were also kept secret.
The same thing applies to the Manhattan project: The general public knew nothing about it, knew nothing about testing the bomb, and didn't even know about Hiroshima and Nagasaki until after the war.
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Instead, I would assume that militaries have advanced AI that we won't learn about for 5-15 years.