>If you can, do you know any books, documents, etc that provide more information about the service in French?
There's a wikipedia article on the "pink minitel" which exists only in French and Occitan.
https://fr.wikipedia.org/wiki/Minitel_rose
Apart from that I'd have to look for more stuff.
Some of the pink chatrooms got in trouble because of "family protection associations" and catholic groups, who are always first in line when it comes to ruining everyone's fun. Can't even jack off without these people taking an interest smh.
fun fact: Xavier Niel, one of the guys who made a fortune on these services, is now the CEO of one of France's biggest internet providers.
>So do younger people in France not care about it at all?
No, not really, unless they have an interest in retro stuff. In my life, my four interactions with minitel have been:
-finding one in my great-grandma's cellar
-seeing a character use it in a comic from the 80's
-3615 usul
-old leftists making fun of millenial and zoomer internet activists ("back in our day we didn't protest on our minitels!")