People are complaining about two opposite things in this thread. 27 inch screen is too small, and 60 hz refresh rate is too low. Problem is that for now, there is not enough bandwidth in Thunderbolt 3/4 to deliver 5K or 6K 120hz displays over a single cable. And apple could not go backward to the retina resolution on mac, the backlash would be insane. So what is the best option? Delivering a 24 inch 4K Promotion display, or a 27 inch 5K 60 hz display? The second option seems to be the better compromise between refresh rate and screen real estate, until displayport and thunderbolt give us the possibility to output more bandwidth for 5K, 6K, 7K 120 hz displays.
So yeah sure you could find great 4K 120 hz displays with OLED or Mini-LED, but they are not anywhere near the pixel density of the apple displays. And I disagree with your last sentence, the difference in pixel density between a 27 inch 4K display and a 27 inch 5K display is very noticeable. maybe it’s not important for you, but that’s an other story