Most of the time I'm using 3: 2 big screens (often browser on one, IDE or similar on the other) and my laptop (usually terminal, or Slack, or a similar auxiliary app). It feels no more complicated to me than swiping between phone apps, and definitely simpler than someone with a carefully curated WM setup.

My screen size has gone up over the years, but that's more a matter of aging eyes than information density. :-)