During university, I lived with four cotenants (two or three of them changing every year, and some in the middle of a year sometimes).
Except for one who wasn't into manga stuff at all (or any kind of cartoon), they were all eager to watch
Dragon Ball Kai and/or read the manga (also pushed some of them to buy the Perfect Edition (Kanzenban), which is easy: you make them read volume 1, they are so amazed by the correctly-translated story and humor that they go on to buy all other volumes of the manga).
Also converted one guy who claimed he hated it (likely based on the little he knew or the old French dub): made him read Kanzenban N°1, he became a total fan. Easy.
Tss, in France, it's rather hard to find a young adult that's not into
Dragon Ball, or so it seems to me (or perhaps university students are more inclined to like it here?!

).
A few weeks ago, I met a friend of one of my cousins at a family event, and sure enough, like 90% guys my age I met though years: he and his little brother liked
Dragon Ball and we went to talk about it a lot and watch the
Son Goku and His Friends Return,
Plan to Eradicate the Super Saiyans,
Episode of Bardack and
Ultimate Tenkaichi's reanimated scenes.
Finally, almost every guy in my "become an English teacher" master were
Dragon Ball fans, so when the teacher of oral class told us to become a teacher for 20 minutes giving a class about anything, I was nice to them:
I made a
Dragon Ball class. It extended to more than 20 minutes though, cause even the teacher knew about the show, and...
well, even when you speed up the process of presenting the show, there's quite a lot to say about the franchise especially when it's an English class given in France, so you have to tell about the original Japanese, the way France handled it from back then to nowadays, and the way the US handled it from back then to nowadays! Phew!
Guys were quite amused when a girl asked me "could you sum up the story?", cause you know, it's not that easy to properly sum up 500+ chapters or 300+ episodes without "dumbifying" the story, so I avoided that by simply telling about the beginning with the Dragon Balls quest and then saying the story gets much more complex and the universe much bigger to the point that there's actually a full encyclopedia just for
Dragon Ball and its many, many characters and events...
So... Yeah, in my experience, in France, it's easy to find a
Dragon Ball fan among young adults, but those seem to also transmit it to their younger brothers or children...
That would explain why Glénat is so unrelentless about releasing
Dragon Ball: Tankobon, Kanzenban, TV Anime Comics, Movie Anime Comics, with several of those at the same time... They just know they still have an ever-growing market waiting for them here, espcially since mangas sell extremely well in France.