Dell P2415Q. https://www.dell.com/en-us/work/shop/cty/dell-24-ultra-hd-4k... you can still find it in stock on Amazon despite Dell not carrying it anymore. I have one, it's a glorious IPS panel for photo editing.

I just picked up a pair of P3222QE monitors. Kind of pricey but hands down the best monitors I've owned. I think it's too big to be "Retina" at 4K, but I really can't see any pixels.

I still find it hard to believe though that I can't change the brightness via the keyboard though in state of the art monitors. Does anyone know of any monitors where this is possible, or do they mostly require you to go through the terrible built in controls?

https://www.dell.com/en-us/work/shop/dell-32-4k-usb-c-hub-mo...

See https://lunar.fyi to change brightness via keyboard