Note the different goals of unifont and Last Resort Font. Last Resort Font is intended to provide descriptive glyphs for all codepoints, even for those that are

Note the different goals of unifont and Last Resort Font. Last Resort Font is intended to provide descriptive glyphs for all codepoints, even for those that are non-characters (which would presumably be out of scope for unifont), and to distinguish between private-use and unassigned codepoints, which would all simply be missing glyphs in something like unifont. The idea is that if you are working on some software that produces or works with Unicode, you can see at a glance what type of character you have (if no other font provided a glyph), or if the codepoint is private-use, non-character, or not assigned yet.