Yeah, what Jim said.
My town has a local con, one that’s been running for over four decades. It is dominated almost entirely by war gaming, D&D 5e, and Pathfinder. Beyond that, most of the rest is board games (typically the ones that take hours to play) and a little old-school stuff (often running actual early editions of D&D rather than newer OSR takes). Attendees are mostly white, mostly male, mostly middle-aged or older, and mostly straight and cis. I started attending about a decade ago, not because I loved any of the games, but simply because I didn’t have a group and wanted to play something with somebody.
But for the past few years, it’s slowly gotten to the point where there’s been one or two indie or story games in most slots. I’ve run Lady Blackbird, Dungeon World, and Fiasco; another guy runs Monster of the Week and three or four other PbtA games every year; a very cool lady facilitates things like Polaris, Fall of Magic, and Taste for Murder. We and a few others now often end up playing in each other’s games, because there is a small subgroup of us who prefer those kinds of games (or who like a mix of trad and indie). It just needed somebody taking the risk of organizing Polaris or whatever at a very grognardy con for some other people to realize, “Oh, there’s other people here who want to play the games I want to play!” and get in on that too.
I will also agree that trad gamers coming over to story games has mostly gone very smoothly, in my experience, as long as they are well-informed before signing up that it’s a more narrative-focused game without a lot of mechanical weight. (Though I have had a couple of disastrous Fiasco games and have sworn off facilitating that with a group of strangers, so it doesn’t always go perfectly.)