Investments from the 90s onward have been more public-private partnerships, but things like the human genome project or a number of cancer treatments and pharmaceuticals have been developed in this manner.
Third, I’m not sure I would regularly expect something as big as the internet to be invented every decade.
Not necessarily disagreeing with you because I feel similar to your comment, but I wanted to dig in a little to see if it’s more truthful or more biased.
I also suspect the push by the uS right wing have impacted the number of great government innovations. The federal role nowadays seems to be to do the core research that is not directly profitable, then transfer control to companies to reap the rewards. (Because of the often incorrect “the government can’t do anything right” narrative pushed in the states)
You can find recent examples too. Also take into account the survivor bias.
The latest technology that got appreciated on HN I could think of it the Mistral LLM, trained on a government funded EuroHPC. It’s a few weeks 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.
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.
Also: Google (pageRank, data centers), Nvidia (CUDA), VMware (virtualization), Qualcomm (CDMA) - many tech companies have leveraged research (and people) funded by NSF.
On the NIH funded/medical side we can look at things like mRNA vaccines, which may be transformative in fighting many diseases.
On the DOE-funded side we seem to be seeing major advancements in nuclear fusion.
On the DARPA side modern self-driving cars (and associated businesses) seem to derive from DARPA's grand challenge in the 2000s.