In an objective sense sure, but regretably there’s no such thing as an objective perspective. A thing is real when it’s taken to be real, and when broad swathes of human life and society are built around a racialized conception of humanity, and when people reductively classed as “white” place themselves at the top of the resulting heirarchy, you can’t just say it isn’t real and end your analysis there. I sympathize with what you’re trying to say, it’s well intentioned, but if you want to really reckon with this fucked up state of affairs, you’ll need a materialist understanding and analysis of why it exists, who it benefits, and the history of how it came about.
Okay? It doesn’t really matter if you agree or not though, I’m right. “White” isn’t “real” in the sense that gravity is real, or even in the sense that the English or French or German cultures are “real.” Yet the world in which we live was and still is divided into whites and non-whites. Whiteness pervades throughout our legal and economic institutions to this day. But you personally don’t believe it’s real, so all of that must be a figment of peoples’ imaginations, right?