(And for coding you actually need height more than width, if you think of a typical layout of a code file)
I still have more than enough room for a few buffers on screen.
I value actual real estate over PPI, preferring to run at 100% / unscaled which looks much nicer in Win10. The 109PPI (3440x1440) is decent enough, and I don't have to squint. Furthermore the DPI matches those of the surrounding 16:10 24s (1920x1200) well enough for it not to be an issue.
The ultrawide allows for this nicely; tests on the left, two actual editors, solution explorer on right, and output at the bottom under the editors.
On a 34" 3440x1440 screen I keep IntelliJ at 14px (10.5pt). On a 32" 4k screen I keep it at 15px-16px (~11pt).
You're still only talking ~100 lines of code on the screen at any one time. Maybe ~130 with a smaller font.