I'm aware of that one, but there are folks who'd prefer to buy an Apple-branded monitor as long as there wasn't anything dreadful about it, for both aesthetic reasons and because there's usually a couple nice touches that aren't on the third-party one. I said $1500 instead of $1300 because I assume any Apple product will cost at least 20% higher than it should. :)

More to the point, it's unclear if Apple is still actually selling that LG display, though:

https://www.engadget.com/2019/05/09/apple-no-longer-selling-...

That headline is phrased as if it's definitive, but of course Apple hasn't said anything. But it's over a month later than that article was published, and the display is still listed as "Delivery: Sold Out" for online ordering, and it appears to be catch-as-catch-can at physical Apple stores: the ones that don't have it just list it as "unavailable for pickup."

I'd buy a $1500 Apple monitor if for no other reason than the fact that Apple would actually put a decent set of speakers on it¹, like they did with the Apple Cinema Display.

¹It's not clear to me if the Pro Display XDR actually has speakers at all, but its audience can be expected to buy a set of high-end speakers too, whereas a monitor aimed at actual users would need built-in speakers.