I cannot overemphasize how useful and important something like that is. Please, make it so.
I just happen to had the same problem; however, I found the solution: using PrintScreen and then I can select the region of the screen I want to copy. When I selected it, it ask me if I want to save it or to “COPY TO THE CLIPBOARD”. This second option is perfect, because I just can use v in LibreOffice to paste it to my document…! It’s a little bit longer than the option in Office, but it works perfectly for me!!!
LibreOffice is an office suite, not a screen capture utility (or a web browser, or code editor, or … etc.). There are plenty of third-party products to chose from (many free) that are better suited to the task of capturing an image of the current desktop, window, or selection.