The Business: Your Failure To Beat The Man Is More Than Just Network Effects

There is one other thing that the discourse on D&D's dominance often omits.

I first explained it going on 20 or more years ago when RPG Net was not an asylum for Commies run by the inmates.

You can play D&D COLD (no prep) and STUPID (no prior knowledge) and THRIVE!

Everyone knows what Dwarves, Elves, Halflings, and Men are. Gnomes? Close enough. Everyone knows what Clerics, Fighters, Magic-Users, and Thieves are. The rest? Varies, but no one will care if there are no Assassins, Druids, Monks, Rangers, or Paladins. Other classes? No one cares. Other races? No one cares.

Everyone knows what you do: delve dungeons, kill monsters, get treasure, level up. Even back in the 1970s and '80s, everyone knew. It's why Current Edition, like WOW, focuses on dungeon-as-theme-park; this is what Normies know the game to be, with everything else being things they need to be taught.

You cannot do this with anything else. Not even the comparable games (Traveller, Champions, Call of Cthulhu) because what those games represent is nowhere near so widely familiar because they are not so narrowly defined in terms of core gameplay loop. Le Indie Darlings and Perennial Also-Rans (RIFTS, BattleTech, etc.) fail as much for lacking this as for anything else.

This is why D&D's competition is only from without: in CPRGs, this is Diablo and its clones; in MMOs, this is WOW; in boardgames, it's everything like TSR's Dungeon (Descent, (Advanced) Heroquest, etc.); in TCGs, it's WOTC's own Magic followed distantly by Blizzard's Hearthstone; then you have your Gatcha, Fortnite, etc. that WOTC says it competes with in its own shareholder reports.

You want to go against D&D? Not only must you go within that Network Effect, you have to offer an equally insta-grokkable--yet different--core gameplay loop that hits the audience demand. You also have to do this within the limits of the Tabletop medium; analog Vidya does not work! WOTC knows that this isn't going to happen unless and until a competent team, assembled by a determined leader, arises to make that happen; given that there is no commercial case to be made for doing this, it will only happen if it is done as part of a larger business plan or as part of a larger socio-political campaign to reshape the greater culture.

No such actor exists, so that ain't happening unless I win the lottery.

Just play D&D.