Lightroom Mobile is not a cloud storage service. You shouldn't treat it as a way of backing up your files. You are merely storing Smart Previews of your files in the cloud space, high-quality JPEGs of your files regardless of their original format on your desktop. The point is that they are there so you can continue editing them in a Lightroom-like environment even while away from your desktop/laptop computer. The files in Lightroom Mobile can only be used in Lightroom Mobile.
This is very different from what is offered by the Creative Cloud storage, which can be used to synchronize your files between any device (that can support the individual files).
The vast difference in how each service works and its intended use is why they are separate.