I used to often reach for xfig for a quick tech diagram (boxes, circles, lines, etc). The "fig" file format, being text, is easy to drop into source control. It's fast and gets the job done. The feeling I get from peers, especially those who've never understood that unix/linux on desktop has long been a thing or really lived that far out of the Win32/MacOS ecosystem, look at you sideways when the file extension isn't .docx, or .ppt or whatever. Maybe SVG supplants fig in all the ways, but I still hope tools like xfig keep their place for quite some time.