I've been thinking more about this topic, because I have spent considerable time and effort pitching D&D 5e to new Gen X and Millennial players; specifically, my colleagues. Not so much Boomers; they're mostly retired.
At my school, I've taught teachers D&D through an introductory game offered on professional development days. This has been very popular. Partly, this is because a lot of the alternatives are SUPER BORING. But mostly, it's because D&D is currently very popular with a significant number of students, and that makes their teachers want to know more about it.
Because they're older, most Gen Xers and Millennials are broadly familiar with the brand "D&D," even if they have no idea really what it is. Most know it's a game that nerds used to play, it involves a lot of dice and elaborate rules, and is now much more broadly popular.
So the biggest selling point for getting older folks to try the game is the opportunity to experience what all the fuss is about with younger folks. To finally try the game that they maybe wrote off as a nerd thing, back in the day.
Oh, and every single person who has tried it, amongst my colleagues, loved it. That doesn't mean they immediately wanted to join a campaign, but they had a great time and, to a person, have become big supporters of students playing D&D, and of tabletop gaming in general.
Edit: I've also taught Dread to my colleagues. It's even easier because it takes almost zero preparation and they still get to experience the concept of a TTRPG.