Dick's doing pretty well in other media too. With Titans getting a 4th season and Gotham Knights coming. Now if he can just get some traction on that movie.
But ya, even Marvel wouldn't be pushing Nightwing like they do Iron Heart or Ms. Marvel. Nor would he be have his own concrete mythos. As what Marvel did with those characters is use the mythos of others to help introduce them to increase their diversity profile of characters. Signal would be an example DC trying to do this.