Could be logging stuff. Mine only ever uses that much CPU when it's showing. Corsair service uses like 1% CPU at minimum frequency.
Still, I wish they split all the crap they put into iCUE into several modules like razer does. We should be able to install the base iCUE just to control our hardware and its included features. If we want software based lighting, temperature overlay, integration with games, etc. we could option in.
iCUE is almost 1 gigabyte in my disk and all I really ever need it for is to be able to use surround sound on my void pro. I used to have an M65 that started doubleclicking after a year and I had a K55 which was NOT compatible with iCUE on release, then after a few months they tacked in iCUE integration for software lighting effects that made the keyboard randomly lockup until I unplugged it.
This combination of bloatware and buggy software really is driving me away from corsair.