> Why are all of these examples of successful government tech investment so old?
There are indeed newer examples such as GPS, RF-CMOS, Lidar, Siri, mRNA vaccines that DARPA invested in one way or another. Not saying they are as spectacular as the internet.
Not to mention that perhaps the low-hanging fruits are all reaped in the earlier years.
The newer tech might just not be as impactful as the yester-decade's, because those impact is already felt, and creating more impact in the face of today is getting harder and harder. Exponential growth is not possible to achieve in practise.
There are indeed newer examples such as GPS, RF-CMOS, Lidar, Siri, mRNA vaccines that DARPA invested in one way or another. Not saying they are as spectacular as the internet.