Currently, when resizing the window too small (e.g. when editing two documents side by side), one loses the arguably most important feature of the status bar, zoom – because it is located at the far right and so just pushed out.

It would be better, if we instead lost things that people tend to use less often. Therefore, we need a priority system that e.g. assigns every status bar element a number, throwing the elements with the highest number out first.

Short example for Writer, informed by my own usage only:
#1  Zoom percentage
#2  Zoom controls
#3  Page number/count
#4  Language selector
#5  Single page/multiple pages/book view
#6  Page style
#7  Insert/Overwrite mode indicator
#8  Word count
#9  Signature indicator
#10 Selection status indicator
#11 Saving status indicator

When that is done, a further idea would be to implement shorter versions of the most space-grabbing status bar elements, like the word count or the Overwite mode indicator.