Just for your (and everyone's) information, every champion benefits from CDR, especially if they manage to reach 40%, the problem is some builds don't allow you to reach that amount because the items they build are more important and/or don't give CDR.
For example, ADCs have no option of CDR except Brutalizer/The Black Cleaver, and even then, you don't get it all the time on them.
AP, Support, and sometimes the Jungler and Solo Top will have enough CDR to make a difference, ADCs have no option for that, unless they specialize into it with Runes/Masteries or tweak their builds. --- The statement below is false. The statement above is true.