And I'm saying D&D's problem is having too many settings to be able to buy into. D&D needs one maybe two, fully developed settings, not 12 official and countless homebrew and 3pp.
The opposite effect though is the generic PC so divorced from the setting that he could walk through a portal from Faerun to Oerth and nothing about him would change.
Because it worked
so well for comics. That's why both Marvel and DC have had...uh...at least one "crisis" story every decade, and have begun to accelerate the pace?
Yes, it can be an ask to have multiple settings. No, that is not profligate waste. "Elseworlds" is popular for a good reason. Folks like variety and creativity.
This idea that you can magically fix buy-in by cleaving out most of the variety and creativity of fiction, locking folks into a single box, is one of the hottest--and wrongest--takes I've ever seen on D&D
anything. I'm frankly shocked you would even suggest that
all of D&D could somehow be imprisoned in the confines of a single setting.
Worse, who gets to decide what's in that setting? If WotC had listened to the loudest shouters during "D&D Next", that would have meant no dragonborn--who are now the second- or third-most-popular non-human race. But picking any existing setting will alienate the fans of
every other setting, and crafting a totally brand-new one will alienate fans of
every setting, on top of having to convince people that this brand new setting is even worth engaging with in the first place.