CCleaner may provide some benefit but only if you are perhaps a power user. Most users will never see the kinds of lagging that cause them to install such a utility.
There are other benefits and some may appeal to you. Personally I don't use it and am pretty happy with how my phone rings anyway. YRMV
I don't worry about CCleaner or other similar apps on my phone either. I love the program on PC for cleaning things up, but have never noticed any difference when using other apps that perform the same function on my phone, so I don't bother with them.
If you only use it for the cache cleaning and don't use it frequently it won't hurt and might help even if only a little. It can and has found, (for me) some space I forgot to clean up from some downloads.