iCUE generally works well here, but they’ve really been tinkering with the software from Corsair themselves lately. It really could be a lot better.

For example, ±2GB of empty RGB profiles are still included as standard (despite the fact that since version 5.x, the installer looks at your existing hardware before downloading this) and other things, and background services (mainly those for communications) have a minor impact on the CPU. The latter issue can be easily solved using the hardware settings introduced in version 5.14, which now work with almost all devices. After that you can remove iCUE from startup and disable all services.

I also now have two sets of LC100 that stopped working after an iCUE update, but they were replaced within a week via RMA.

I can adjust the RGB for the ASUS motherboard and GPU in iCUE without Armoury Crate, which then also syncs with the Corsair hardware.

So most of it is there, but all of it is “not there”. By the way, this is nonsense from manufacturers who have all the RGB, and iCUE is definitely here. Another one of the best. Free alternatives quickly make you dependent on a community that also has to update everything (eg OpenRGB), which sometimes takes a while.