Percussive enough to be a whole rhythm section
Surely, you jest, buddy.
Let's see. 2 or 3 fingers plucking 4 strings is a rhythm section? How about a pair of sticks and a pair of feet, all a blur of fluid, adhesive, and cohesive motion.
A rock act can't do without any instrument. But without drums, there's no band. No rhythm; no band.
And let's not forget some of the other contributors to the collective that may come to be known as a unit. Say, lyricists? Without a great lyricist, you just have people banging on skins and plucking on strings while someone belches meaningless drivel into a microphone.
Or worse, you get things like:
I get up at seven.
yeah.
I go to work by nine.
Got no time for livin'
yeah.
I'm workin' all the time.
Seems to me I could live my life a lot better than I think I am.
I'd continue, but it's really too painful. Bad enough that "yeah" is considered prose. Worse that "seven" is supposed to rhyme with "livin'" and "nine" with "time". Unforgivably, the last line uses "am" instead of "have". If the "lyricist" really wanted to use the word "am" (likely, since he rhymes it with "man" in the next line), proper usage of the language would dictate "It seems to me I could be living my life a lot better than I think I am."
And yet that author gets all the credit nowadays because he sings songs written by a REAL lyricist. Of course that band went nowhere until they did get a real lyricist.
Drummers and lyrcists make rock bands.