The documentation header on this page used to (not long ago) used to have a dropdown submenu, including access to the reference pages, but today, I see it's gone - useless.
When and why?
Sure, I can click on Reference within the IDE and get there, but???
Sure the hamburger icon hides the content, but it still reserves the real estate.
The "unwanted" part is that it seems to take up eyeball real estate that I would prefer as part of this dinky text entry window or the 50 char code viewing window. Why does one need the always-on-screen top-level one-click cruft that doesn't even have a RTFM link.
Sure, the research done for for ad/sales sites shows you get more revenue with large off-topic side bars and dinky content, but there's a reason why VSCode can use 90%+ of the screen for content.
it might be a difference in window size? I do my work on pretty large screens and run large browser windows, and the space for the hamburger panel remains the same constant size and is either populated or empty, leaving the edit and code boxes the same awkward, narrow width.
For me, the hamburger menu merely toggles the content and doesn't change the layout.
All the fancy CSS stuff makes different people see different things on different screens in different browsers on different OSs, which makes it hard to tell if things are working as designed or not.
I see what you mean and I see the same thing when working full screen, which is not how I normally work. However, to be strictly correct, what is happening is that the "hamburger" menu is actually being turned on and off rather than just the contents being cleared. Note the the vertical line between the "hamburger" menu and the rest of the screen is visible and invisible along with the menu contents
You are making a false correlation. The maximum content width was limited the same way even before the introduction of the sidebar, as we can see from your own post discussing the subject a year ago, before the switch to the sidebar navigation menu:
As was also discussed in that topic. the content width limit is an intentional choice made by the designers of the Discourse forum framework:
The sidebar only occupies this previously unutilized space.