I think even Windows does some of this by searching and indexing everything all the time. I don't like them, but a graphical file manager, show the file as an icon, mouse hover over it and get an extended "tool tip" description.Yes, IMHO, sidecar files with the rest of the information or a database make far more sense. Also, depending upon the type of file there's often times the ability to search the file itself for information. Plus, there is the strings utility, so even if it is a binary format you may be able to get data from in there as well.
A shell script that does a find and strings could automate 90% of it.