In terms of usable space and legibility, it's actually a bit of a downgrade. You're looking at a high refresh gaming display against a pair of IPS. You're looking at 4k crammed into a 'tiny' 28" space vs. a pair of 24" 16:10 at 1920x1200.
Whilst sure, you'd be going from 3840x1200 to 3840x2180 in terms of resolution, the increase in PPI would just force you to higher display scaling resulting in less usable space.
See my media center, where sure I've got a 55" 4k display, but to even have text legible at a mere 4 feet I've got to run windows display scaling at 200%... so basically in terms of useful space it's got less than the 28" 1440p IPS I'm running as the center display on my workstation. And as much as you might think 4k would help legibility once you start scaling, the drop from IPS to 1ms response LCD does you no favors on colour reproduction. Though if you care about gaming, an IPS' low response times do you no favors either.
1440p seems to be the ideal upper-limit for 28" in "normal" usage cases in a desktop monitor at what should be a normal / comfortable viewing distance of two to three feet., and even then you end up running 150% scaling to match the 125% you typically need for a 24" 1920x1200 display.
Unless of course you're one of these users making themselves sick all the time by leaning way the blazes in plastering your head inches from the screen. Aka what I see people doing all the time on 4k laptop screens because they don't even know how to set font/ui scaling... though I see desktop users do it all the time as well.