From being on the inside for a short period of time, I've had a glimpse at just how hard this is. Projects come and go, getting killed for budgets, politics, etc etc
The commitment and early vision, are very difficult to re-create.
I'm most familiar with WiFi as I worked with one of the inventors. It was patented in 1992 based on research in radio-telescopes for detecting black holes, which had been done years earlier.
If you think about what most computers were like, and what we were doing with them in 1992, WiFi would have made no sense. It would have made less sense when they started work on it.
Most computers were desktops, you didn't take a laptop to get a latte (which was also just barely a common beverage). Most people didn't have the internet, so there wasn't much to connect to. Your computer didn't move, so why have it wireless. Mostly you'd connect to a printer, which was also huge, so may as well be wired.
There was nothing you would do on the network which would use the speed that WiFi was capable of.
It would be almost a decade before it would be somewhat useful, and not until 2008, with the arrival of smartphones that it was a necessity.
So yes, I believe most countries should try to support a DARPA like environment. I don't believe most countries will be successful in their attempt.