This is true, but only to the degree that it's true of individual personality. Given that a person can't speak for anybody else, and certainly not everybody who happens to have the same skin colour, any claim of "identity" on that basis is just projection. There's no such thing as the "holder of an identity." Only the "holder of a set of experiences and biases and beliefs that differ from everybody else's."

Again, we understand this perfectly well for white people. The idea of a white identity hits the ear strangely because white people aren't seen as a homogenous lump. The individuality off white people is respected in a way that black people's isn't (at least except from the recent woeness about all white people being racist, fragile, etc.). The idea of identity is simply a way of simplifying the complexity of people with black skin. Of treating them as something other than full human beings.

The fact that some black people have embraced this idea too, doesn't change the fact that it makes no sense.

And no, it's worrying that you see my last sentence as an attempt to declare anything by fiat. I'm not trying to "create" a world. My last sentence is a simple statement of fact. All of the suffering that black people have endured throughout recent history is the result of a failure to understand (and recognise) the simple truth of our full humanity. If you're struggling with that concept, there's a lot you need to think about.