D&D is pop culture AND nerdspace, with a slight lean towards nerdspace. Pathfinder is nerdspace.
Just imagine the most average guy imaginable at the pub, and evaluate what are the odds he's heard of a specific topic. If you're like "There's almost no way he's heard of this", and it's a nerd topic, it's in nerdspace.
Like, I expect the average 25 year old athlete to have probably heard of or watched DBZ, or Attack on Titan, or a Jojo's, or something like that. That's some crossover nerd material. If they have a Crunchyroll account so they can watch isekais, then they're probably just an athletic nerd (like a Tim Duncan).