... how for christ's sake one can seriously work with that multi-window default design. Who is advocating it, and why?
I don't think anybody is really advocating it but AnchorDocking used to be buggy. Now in 1.8 it works rather well. Please test.
I hope the possible remaining issues get fixed soon.
I mean, given that most of us have multiple programs running, a browser, an e-mail application and a bunch of development tools at least, how do you manage switching between and distinguishing between applications?
By using virtual desktops. I personally use KDE but the concept is implemented in many DE systems.
So, one virtual desktop here is dedicated for a console and Lazarus started from it.
Yes, I like separate windows better than a docked IDE, because:
1. Windows can overlap each other. A small visible part is often enough to see what is going on. See my Messages window in the screenshot. The visible part shows that compilation happened and succeeded. When I need more info, I select the window.
2. Source editor can be from screen top to bottom. I want to see as many lines as possible at a time. For the same reason the editor toolbar is located left side. Sometimes I want to see 2 parts of source code at the same time. Then I open another equally high editor window, moving them side by side.
The screenshot is what I happened to have open now. In debugging situations I often have stacktrace window and maybe other debug windows open. They can overlap the OI which is not needed then.
All in all, this means more efficient usage of screen area.
I fully understand your point in a system without virtual desktop. The sole desktop can become messy then.
The OS in the screenshot is Manjaro Linux with KDE. I used to have 4 virtual desktops but now just 2 feels enough.
[Edit] I had to scale down the screenshot to match the forum's file size limit. It became messy but you get the idea.