On a laptop typically I'd only have one window 'open?' maximised at a time. It allows focus. I'm a big fan of Gnome3 for this.
If coding then an additional monitor can help, the additional monitor multi-window to support the main focus.
If writing, then one screen and paper and pencil to sketch thoughts.
If diagramming/flowcharting, switch desk or stand up and use a whiteboard, reduce over multiple pieces of A3, then the finished result should be refined enough to iron edges out to formalise in Dia or Visio. I also prefer pencils over pens, have a box of multiple colour pens, crayons too, bunch of sticky notes not for the screen but supporting paper-based thoughts, masking tape for putting things together. And this is me working by myself.
We all have our use cases and it's rarely one size fits all.
For wikipedia - why not default to whatever's deemed best for most, but have a small toggle button for 'old'.
Modern operating systems only give you one mouse cursor and one focus at a time. What are you doing in the other windows when you are trying to read wikipedia?
Are you saying you only have one window open at a time?