I use multiple virtual desktops, for dev I have a terminal on the left and the IDE on the right. This was the best config I could find where I had enough on the screens I didn't need to flip between panes frequently, yet it wasn't overwhelming and lets the actual window view behind the displays through, and I can comfortably focus on key areas and look around with craning my neck too much.
If the displays were backing a wall, I might try an 8k 65" display, but I would mainly use the comfortable part of it, and let the rest be ambient info. That could be magnificent with an OLED display. Though I think it would make sense to be curved and they aren't common anymore. Who knows, maybe a VR headset will be a better choice in a few years.
I've been working a lot on the idea of ambient info. I use KDE's html wallpaper feature to provide a dynamic graph view of my environment.