Yeah, I'm black and I have many family members that are gay, female and not white, so that stuff doesn't work on me, because I am more than aware the kind of people I live with and interact with on a daily basis exist.
More to the point forced diversity does exist, it's pretty much the only reason Ironheart exists, and don't try to compare Riri to characters like Bucky, Dick Grayson, or Wally West, people like those characters because they're well-written something that wasn't applicable to Ironheart until her most recent series, before then all we got were dumb moments where she stole from other people to make her suit while never being called out on it, that dumb backstory where she disrupts her class just to get her teacher to oppress her dreams, and another point here is all those characters actually had history with the person they replaced, whereas Riri just pops up in Iron Man a couple of months before Tony gets put in a coma and takes over his book and is suddenly given a ton of undeserved importance.
And it's been pointed out Riri is completely redundant since War Machine has a niece Lila Rhodes, who's about the same age and is a genius and could've taken her spot in a way that would've been way more natural since unlike Riri she actually has ties to Iron Man that would've justified her place in the story.