.By way of anecdotal support for this idea, this article doesn't really track popularity over time, but it does make the point that TTRPGs are "increasingly becoming a mainstream activity" and says that Stephen Colbert was a big D&D player, and once even issued an on-air shout-out to “any half-elf thieves who are joining us tonight.” Again, purely anecdotal, but that would never have happened in the 80's or 90's.
I'd argue that if media was as prevalent and expansive as it was today back then you WOULD see someone giving a shout out to D&D on screen.
In fact didnt TSR balk at allowing Spielberg to use actual D&D stuff on screen in E.T.? Which is why the game the Mike and his friends are playing at the kitchen table early on in the film is very D&D like without anyone ever calling it out specifically as D&D?
Also D&D had a Saturday morning cartoon. It had ads in both Marvel and DC comics. Even if you were NOT an RPG geek you at least had some exposure to it. Now? Not so much. The TTRPG Community is very insular.
I was a black kid from Bushwick Brookyln in the 80's and even I knew what D&D was because the ads in my favorite comicbooks.