In my similar filter, I tried removing the carbon cartridge from the "sleeve" after a while, a PITA. Then I added small "bio-bits" I had, another PITA. & the sponge/ floss part sagged & bagged down so it didn't cover the entire area. The water probably took the path of least resistance, less water flowing through the "bits". Not worth all the effort IMO.
Beneficial bacteria grow on any surfaces, as Badger agreed. I usually only use carbon (charcoal) to remove meds but it doesn't hurt to have it at other times. Carbon has very, very tiny openings, ceramic bits or rings also have many small surfaces but nothing like carbon. Meds (& bacteria) are adsorbed (not quite the same as absorbed). All filter media soon holds too much "gunk" to be more than reduced surfaces. I used to rub & rinse off some of the ceramic's "slime" for the same reason I rinse & squeeze out sponges. Yes, I might lose a bit beneficial bacteria, unless I use tank water. That's why I like 2 filters on most tanks. &, heaven forbid, I rinse in tap water (ahem, not for the small 1 tank,1 filter owner. Use tank or dechlorinated water to rinse media). Do as I say not as I do, my tanks are different than yours are & so is my routine.