So the argument is what, that the white people who had a ‘role model’ for their kids shouldn’t be annoyed that the industry is removing that role model, because race shouldn’t matter. But also that race representation matters, and that it’s important for other races to have representation by taking over the roles of those figures.

Regarding Doctor Who, Nguti will not be the Doctor forever. He's just one of many. Whether or not he was specifically chosen because he's black or not, I don't know, but I don't see any inherent problem with the Doctor being black. Race shouldn't be core to the identity of the doctor.

I mean, we’re busy watching young guys flock to alpha dumbass influencer bros, in part because there are fewer and fewer positive role models for them to look up to.

I think this is a much wider issue beyond the casting for Doctor Who. I'd argue the general decline of entertainment monoculture in general plays more of a role here than any particular creative decision for remakes or reimagining of TV series and films.