I get crazy ideas when I'm half asleep. So here's what my sleep deprived mind thought should be valid English -
"This is one of the many few reasons why [noun] rocks"
That's right, MANY FEW.
It somehow sounds better than either "many" or "few" by itself. More rhythmic, balanced.
Plus it's handy when you want to emphasise the "few" good reasons but in a positive sense. Like when you want to point out the best feature of your product
but make sure that the customer knows that there are other features that are just as good too
but not trivialise the very important feature you are explaining right now
but... Forget it.. I did warn you that it was a hair brained idea..