As an aside, people forget how scifi France was and, to a certain extent, still is. Jules Verne was French. Paris is/was "the city of lights" because the French were early adopters of electricity. Descartes, Lavoisier, Fourier... Even the Maginot line was a high-tech approach to national defense, and the French were willing to give it a shot. I'm actually surprised that France hasn't done much, much more to foster high-tech startups. Imagine if they made some reasonable Paris suburb a free economic zone!
A tiny blip of history, state companies did impede some evolution, France Telecom wanted to ensure use of their system (x25 ? x500 .. I forgot) meanwhile TCP was growing in the US. Sometimes large public companies are great, sometimes a bit less so.
Nevertheless in 1980 the France Telecom (called PTT at the time) brought the highly successful Minitel system to life - basically a text mode WWW running over phone lines.
I’m not sure what the extend of the delay really is, maybe in the 90s it could be felt but since the 2000’s, it seems like France’s internet is always pretty fast and cheap and available across the country.
How I see it, network teachers who told this story, said it as a missed technological leadership opportunity. They had lots of skills but the structure made networking lag just a bit too long.