[bluefirebrand]

There are two problems

Problem 1 is that D&D is the most popular and well known TTRPG, so people who are otherwise not curious about roleplaying games might still wind up playing D&D. They might not even realize there are other similar but different roleplaying games to even play!

Problem 2 follows from problem 1. Because D&D is seen as the 'default', many people try to make it be the one-size-fits-all game. It is actually really bad at this, because it has it's roots in a very specific type of tabletop wargame that is still visible in its DNA even today

So very often you find people who would probably prefer a more roleplaying focused game, playing D&D instead. And despite Wizards of the Coasts best efforts, D&D still plays better as a dungeon crawling wargame style game than a pure roleplaying game

My evidence of this is the insane popularity of Baldur's Gate 3, mostly because it had a lot of deep dialogue trees, not so much because it's a good tactical combat game (even though it is pretty good at that)