A couple of small quibbles about the optical fiber thing:
1. 17 dB/km attenuation fibers were first demonstrated 52 years ago, so better materials than precisely 50 years ago were not necessary for switching global telecom from copper over to fiber optics. That is, the materials science revolution in question wasn't "in that period", but immediately prior to it. Otherwise, everything you said is correct, as I said before.
2. Since the ARPANet started working in 01969, 53 years ago, long before the actual switchover to fiber optics, clearly wide-area packet switching wasn't dependent on fiber optics. When I first started using the internet in 01992, I was sharing a VAX with dozens of other students, all using a 64 kilobit per second frame-relay link, but the WWW was already up and running, and I used it at the time. Of course the NSFNet was running over optical fiber at the time, but if microwave waveguides had been the only available gigabit-capable communications medium, I'm confident they would have been laying microwave waveguides. Relay lines of microwave towers would also have worked.
The crucial inventions of the WWW were HTML, HTTP, and the URL; from my point of view, those are fairly independent of computer speed and even bandwidth. I mean, yes, there's a minimal viable computer for parsing HTML; but as it turns out it's a Commodore PET running Contiki. All the improvements in computing speed and memory size in the last 45 years are unnecessary for running the WWW.
You could imagine an optical-fiber-free internet where the server-centric nature of HTTP was an unacceptably heavy burden on the more limited backbone, especially with 6502-class CPUs constantly refetching pages in order to handle scrolling. Replacing HTTP with something like Usenet, BitTorrent, Freenet, Fastly, IPFS, or Kademlia is probably enough of a solution there. Maybe you wouldn't have YouTube or NetFlix, but that's why I didn't include YouTube or NetFlix in my list.
1. 17 dB/km attenuation fibers were first demonstrated 52 years ago, so better materials than precisely 50 years ago were not necessary for switching global telecom from copper over to fiber optics. That is, the materials science revolution in question wasn't "in that period", but immediately prior to it. Otherwise, everything you said is correct, as I said before.
2. Since the ARPANet started working in 01969, 53 years ago, long before the actual switchover to fiber optics, clearly wide-area packet switching wasn't dependent on fiber optics. When I first started using the internet in 01992, I was sharing a VAX with dozens of other students, all using a 64 kilobit per second frame-relay link, but the WWW was already up and running, and I used it at the time. Of course the NSFNet was running over optical fiber at the time, but if microwave waveguides had been the only available gigabit-capable communications medium, I'm confident they would have been laying microwave waveguides. Relay lines of microwave towers would also have worked.
The crucial inventions of the WWW were HTML, HTTP, and the URL; from my point of view, those are fairly independent of computer speed and even bandwidth. I mean, yes, there's a minimal viable computer for parsing HTML; but as it turns out it's a Commodore PET running Contiki. All the improvements in computing speed and memory size in the last 45 years are unnecessary for running the WWW.
You could imagine an optical-fiber-free internet where the server-centric nature of HTTP was an unacceptably heavy burden on the more limited backbone, especially with 6502-class CPUs constantly refetching pages in order to handle scrolling. Replacing HTTP with something like Usenet, BitTorrent, Freenet, Fastly, IPFS, or Kademlia is probably enough of a solution there. Maybe you wouldn't have YouTube or NetFlix, but that's why I didn't include YouTube or NetFlix in my list.