Another factor is that focusing on pixel density above all else comes at the expense of pixel speed, there are no large monitors which meet Apples 220ppi standard and have a refresh rate of 120hz or better, no matter how much money you're willing to spend, they just don't exist.
I think the display resolution market suffers from some opposing directions: people who do productivity work like high resolutions, but since Windows (majority of the market) still seems to struggle to scale UI elements correctly some people prefer lower resolution. Also, gamers associate high resolutions with heavy GPU requirements or lower framerates. And then there are companies that are used to spending the absolute minimum on screens that are barely 1080p.