D&D is so dominant it's more or less the only system you can count on any given TTRPG player knowing, and often there's a lot of resistance to learning any othe

D&D is so dominant it's more or less the only system you can count on any given TTRPG player knowing, and often there's a lot of resistance to learning any other system. It makes sense for it to evolve into more of a blank slate system that is flexible by default so you can add your own spin on top, and that's a lot of how it's been evolving, because it adds to the ease of playing and running a game. A really good DM barely needs a system at all, and a terrible DM will be awful even given a great system, but the ruleset makes a difference for the majority of DMs that are somewhere in between.