Isn't that just how technology works? We've technically had the Internet since the 1960s, but it has grown and developed and changed enough that the Internet we had in the 1960s wasn't really what we'd call "the Internet" today (the world wide web). It takes a long time for anything to go from the first time someone hacked together a semi-functioning prototype to widespread adoption, especially when it's the 0 to 1 type of innovation Thiel is so fond of.
Who is to say there are no technologies that are now in their infancy that won't reach widespread adoption 40 years from now? Who is to say what's in its infancy today won't be just as impressive or groundbreaking as what was in its infancy 40 years ago?
I imagine this depends on one's perception of "shift", but as someone who's been using the commercial Internet since the late 80's, in my view the world wide web only went through one fundamental shift - that was from static web pages to dynamic ones (CGI, at the time).
Programming tools, languages and paradigms (client side v. server side, MVC v. layered, and so on) have evolved for sure, but the WWW? Nothing fundamentally new since the early 90's when CGI made its appearance. The web works today as it did then, albeit with fatter pipes and obese page payloads.
There wasn't an "Internet" in the 1960s, or at least, not until the very end. The various components: TCP/IP networking, BGP, ethernet, ATM, protocols, Unix, etc., simply didn't exist.
There were some computers which could communicate over modems at 300 - 9600 baud or so, at distance.
The real guts started filling in during the 1980s, particularly BSD Unix (with a TCP/IP stack), Perl, and by the end of the decade, the first Web server and clients.
The difference between technological developments of the latter half of the 20th century and those from 1800 - 1950, is that the former involved new sources of energy, new means of producing and distributing it, and exceptional advances in materials. From 1950 onward most major advances have been in information processing and communications, though the Green Revolution likely also counts. Nothing to sneeze at, but limited all the same: information processing lets you change how you manage matter, but the overall impact is still restricted to the theoretical maximum efficiency of those physical processes.
Faith that technology will provide us with an unlimited future is ... wishful thinking.
Who is to say there are no technologies that are now in their infancy that won't reach widespread adoption 40 years from now? Who is to say what's in its infancy today won't be just as impressive or groundbreaking as what was in its infancy 40 years ago?