thank you, that's what I was asking forChris Perkins talked about this in a panel a few years ago, I got the numbers wrong:
"A great bulk of D&D players (55%) play homebrew, but about 50% of those homebrewers pillage from other settings for their own world. About 35% play in the Forgotten Realms, and then everything else takes up 10%. Very few people are running Dark Sun, Hollow World or Mystara campaigns. Greyhawk may be 5%."
Chris Perkins gave a seminar at GameHole 2015 about Wizards’ future plans for D&D adventures and products. The Gaming and BS Podcast recorded the seminar and posted it. I’m very grateful to them! There were a lot of interesting topics covered in the seminar. I’ve written a summary of some of the...merricb.com
I doubt that this has changed overly much, given the popularity of homebrewers like Matt Coleville or Matt Mercer out there.