geko I don't understand why the fascination of users to enroll a third party in storing data, why upload anything if its really important/sensitive, just use encrypted UBS sticks or external drives that are stored securely.
In some places of the world, activist might get frequently harassed by authorities, and have their property searched without legitimate reasons. If you have documents that prove corruption in the government that you intend to leak, this might pose a big problem for you. Using Tor to connect to an anonymous account on an encrypted cloud storage service, and only storing data there, and nothing on your devices at all, might in fact be beneficial, as the authorities will find nothing when searching your devices, and will not know that you have a cloud account and even less what is on there. An encrypted USB key the find you might be forced to decrypt.
My point is, there are cases where using a cloud storage is the only safe way to store sensitive information.
But for most people, using encrypted USB drives are probably preferable to cloud storage for many reasons. I am not letting any of my data ever touch any cloud service, or even internet at all. Back when I still used cloud services for backup, I uploaded and downloaded manually, and encrypted everything myself, in a single archive with padding, so I could know for certain I leaked no metadata, and that everything was in fact securely encrypted. But I felt this was still a little risky for me, if my password leaks, I accidentally uploads the unencrypted archive, or the encryption algorithm is broken in the future, or any of many other reasons. They still have my data after all, just encrypted. It is better if they don't have it at all.