Sure, that's true as far as it goes. But as long as diversity remains limited to supporting characters instead of the actual central characters, as long as we're still being asked and expected to view even the most diverse setting through the viewpoint of a white man (or an Asian character played by a white man or woman, which is even worse), then there's still a glass ceiling that needs to be broken. Being the star makes a huge difference. Black Lightning on The CW is more of a breakthrough character than Spartan or Kid Flash. Black Panther is more of a breakthrough movie lead than War Machine or Falcon. Wonder Woman and Captain Marvel are more important breakthrough roles than Lois Lane and Pepper Potts. Doctor Who has always had female companions, but Jodie Whittaker becoming the actual Doctor is a much huger deal. It's always been okay to have diverse supporting characters, at least for most of the past half-century, but it's been a long, hard fight to break through to lead roles. The difference absolutely does matter.
Heck, I've felt that way since I was a kid. I'd see all these ensemble casts like Star Trek and Barney Miller where you had diverse supporting players but the top-billed actor was always a white man, and that just didn't seem fair to me -- why can't someone else get a turn at the top? I was taught from an early age that it's polite to share your toys, to let everyone get their turn on the swings. And even aside from any fair-play considerations, it went against my deep-seated desire for symmetry and balance. I guess that's why the majority of the lead characters in my original fiction are female, nonwhite, or LGBT -- just to try to balance things out.
