good deal considering it's much smaller and twice the price

Yes really. A pixel is a pixel. This dell monitor has pixels the size of boulders. Apple Pro Display XDR has 4.6m more pixels in a significantly smaller area creating a much denser display.

Denser pixels are worth less because you can't see them; in this case 3x-4x less.

You CAN see then, you CANNOT distinguish them apart without a closer look.

It would be a really ineffective monitor if you couldn't see the pixels.

macOS can specify regions of the screen to be 1x. If I'm using Capture One or Lightroom, my photos are at normal resolution while the UI elements are "retina/2x".

So you can see more detail but you aren't fitting more photos on the screen.

You can configure macOS to scale everything more or less, just like you want it. Same for Windows and Linux. And you keep the crispness of the full pixel resolution for text and images.

Retina pixels what? Pixel is a pixel, density _of pixels_ is what you're looking for

"Retina" is Apple's marketing name for high PPI displays.

Exactly. Retina is not "pixels" though or type of pixel

I think they mean "but those pixels are very small, right?"

6016 x 3384.

Dell monitor is twice the surface area with 3/4 the pixels … or in reverse: Apple display is half the size with 30% more pixels.

(edit: corrected dell pixel %)

What is going on here? Why is everyone in this thread using 'pixels" to mean ppi? It seems unnecessarily confusing or even misleading. I mean blatantly a 6K monitor has more pixels than a 5K or 4K one, regardless of the pixel density.

Yeah, nobody’s saying a 5k monitor has more pixels than a 6k.

I think what people are trying to communicate, but struggling to, is that high pixel count on a huge display can be deceptive.

I think grandparent was trying to say “comparing a low-poi display to a high-ppi display is not a direct comparison.”