"chars" is only slightly shorter than "graphs" (one byte (utf-8), codepoint and grapheme ;-).

I think in general it pays off to think about which kind of length you want. If you want to insert stuff into a database, and have to care about size limits, you'll probably care more about bytes or codepoints (depends on how well your DBMS handles Unicode).

But you're right, most of the time the programmer is interested in graphemes when dealing with text processing.