I'm not necessarily saying you are wrong here in the case of fortnite, but do you have data to back up that the average fortnite player is an adult? It seems like in general it tends to be wildly more popular with younger people, generally kids and teens - although i don't have data for this either, just based off what I've personally seen.
I have no data but anecdotes. I'm in my 40s and whenever I played squads, trios, or duos, I was playing with people in their 20s or 30s. Also, it's one of those rare online games where you can queue in at 3am or in the middle of a school day and almost instantly get into a game, and it's a game requiring 100 people per match. Other online games I've gotten into, 15 player games, essentially died out late at night or during schooldays. Fortnite doesn't.
Yes, there are a lot of kids playing it, and it's very popular with them. But there's also a huge audience of adults.
My anecdata, my teenagers won't play it, despite liking it [privately], because it's for "little kids" -- by which they mean Primary School (7-11yo) children.
They are ridiculously sensitive to their perceived age groups for games.
