When updating drivers and software simultaneously ccleaner suggests to restart the computer when either of them is finished not taking into account that this will disturb the other process that is still running. Especially the interruption of driver updates can lead to errors.
I think this could easely be prevented in the software.
Well it does ask if you want to restart now or later - so it’s entirely your choice. (And your error if you restart too early).
The thing I would say is that if you really want to use the driver and/or software updaters then you are probably safest doing one thing at a time rather than multiple updates all at once.