The biggest thing that I've seen D&D offer is support for campaign play. Systems like Blades in the Dark, Heart, and Mork Borg are great, but they are built around the assumption that characters are replaced (or in the case of Mork Borg, the world ends) regularly. A lot of other systems also tend to abstract away treasure in a way that I think is less satisfying for some players.

Personally, I'd love to see more systems that are less "wargaming" oriented than D&D but with a focus on long term play and, where possible, player growth.