The reason Americans don't realize that the USA floats on weapons sales is because, unlike smart phones and search engines, there aren't just 2 or 3 big companies who make them. There's no weapons manufacturer with Apple or Google's market share or cash reserves.
There are, however, several dozen with 1/4-1/3 their values+reserves and they have something none of the big name tech cos have: RENTS and MASSIVE JOBS LEVERAGE. Cos like Boeing, Lockheed, Raytheon get big $ like clockwork from the Pentagon, their credit dwarfs Apple/Google, etc.
Tomorrow, some unheard of Asian co might come up with an iPhone killer and another a search engine that runs on quantum servers and put both of them out of business; ie their futures are hit and miss. Not so with the $350+Billion a year subsidized weapons makers.
Another possibility is all top *defense contractors* to merge. So, why haven't they? This should be obvious if you read the first tweet in this thread. That would make that co stand out like a sore thumb because its worth would make Apple+Google's value look like pocket change.
And, remember, I'm not just talking about those 2 companies - toss in Microsoft and Oracle and all the ISPs and Telcos and automotive manufacturers -> and that merged *defense contractor* co would still have more money AND CREDIT AND JOBS LEVERAGE than all of them combined.