iCloud use as storage and not "reflective" like dropbox
iCloud is not 'storage' it is 'data distribution'.

It isn't designed to 'keep things on', it's designed so that whichever device you pick up, you have access to the same files.

The closest it comes to being 'storage' is if you have a small, overloaded drive it will start to offload such as full-size images, leaving smaller versions locally.

Purely personal opinion:
Many people were sold laptops with far too little drive space on them &amp; are now paying the price for economising/marketing strategy.
256GB is absolute bare minimum, imnsho, &amp; 128GB is simply not enough for much more than the OS.