I've never really seen it as multi-tasking, just that a lot of knowledge work involves inputs and outputs (edit web page/ previous web page, edit code/view test results, read requirements/write spec etc). Those can often be separate windows and being able to focus on either at will works well for me.
I guess that’s where the ergonomics kick in and break it for me. I gotta mention that I wear glasses, so everything not in the center of my vision is basically blurred. Which means lots of head turning with dual or wide screens.
I found something with an effective resolution of about 2560x1440 to be a sweet spot, where I can fit windows needed for a single task in one screen. Provided those windows don’t waste too much space with unnecessary stuff of course.
Gotcha. I must admit on Linux especially where I just have Ctrl+1, Ctrl+2, Ctrl+3 mapped to virtual desktops, I'm not unhappy on a single screen. I'm just aware that 20 years ago when it started to become more common, it was one of the few completely black and white productivity gains you could get as a programmer (alongside solid state disks). Seems odd if that doesn't hold in general today.
I quickly realized I absolutely hate setups with multiple monitors, when I was given one at work. I quickly gave back my second monitor, because it just made it worse for me, and additionally wasted space on my desk. If you want to improve my circumstances at work, give me a bigger monitor, not more of them.
I've never used multiple monitors. I've also never talked about that fact, because why would I? Only people who use multiple monitors have reason to talk about them, so discussion is biased in favor of seeming like people use them.
(I've never even tried multiple monitors. I could immediately think of several reasons why they would not be an improvement for me, so made a quick decision in 1998 and moved on.)
