I much prefer a 4k monitor as my primary, and my laptop below it (open, as a small second screen).

Going outside, working just off the laptop, is a definite shift. It usually means less coding, but sometimes it pushes me to be productive in areas I normally neglect (documenting, planning, organizing).

To do real development, I am very dependent upon a big monitor. If I travel, I take one or rent one.

Honestly though, sometimes I just go for a walk. And often during that walk, with no screens, my brain magically sorts through some problems and gives me new insights.

If you work from home though, most people agree on dedicating some space and properly equipping it. Working always only on a laptop in a floater kind of way is something that I suspect most people cannot do with any real level of productivity.