Different engineers do different work. Not everyone is running 10+ processes and referring to reference guides all day, some, like myself, spend most of our days writing emails or reviewing PRs, neither of which really necessitate lots of screen real estate.

You're not looking at and digesting all of that information at once (unless you have an impressive dozen sets of eyes :) ). You're context switching, and you've found that the most productive way for you to context switch is to have everything fully available at a glance. For others, being able to switch at a literal glance is less productive and more taxing (those 10 process can be distracting!) so we use different tools or methods, like workspaces, tmux sessions, terminal tabs. I usually have three projects each loaded and available for attention at once with a key press, but I don't need (nor do I want) them actively visible alongside each other.

Virtual desktops and 3 finger swipes for me too. I cannot understand how having multiple apps visible helps, because you have to continuously switch your eye focus and if you have distracting apps like Slack in your field it's even worse. So laptop with 1 window maximized is the best for me. And the mobility that it allows: move to the sofa, armchair, cafe, I even deployed from a taxi. I tried to buy and use external keyboard and trackpad on my standup desk during the pandemic, but I returned the same day - the distance between the position of keys and the trackpad was so weird after years of laptop only.

thinking about it, I'm probably really biased. I do robotics, so live analysis of sensors, processed data output running on a real platform as well as involved simulations is part of my process. I need to be able to glance at data and plots quickly without changing my current screen

For sure, one thing is setups are very personal and we shouldn't try to all normalize to the same one.

On windows I alt tab often. I close anything not related to work keeping the list of windows short (maybe 5 at most). Split screen some where appropriate.

My home office is 2 monitors. My work office is 3, however I only find myself using 2

I have 8 full virtual desktops. I can switch screens without even moving my head.