Updated 20-Sep-2023
The point of this is to free the cloud, though we won't have full rights for a while (total freedom), still quite a bit can be done within the cloud.
First, Drop Dropbox
The first step is unintuitive. Drop Dropbox. Yes, that's right. Dropbox is a cul-de-sac in the evolution of the Internet. It isn't going anywhere (even though it has become ubiquitous). The first thing is to get out of this rut, and by doing so awaken the senses to other options and the needs Dropbox had lulled us into not believing or being aware of.
Second, Security and Encryption
Once Dropbox is dropped, then we have basic security problems. This is largely being solved by Cryptomator an open source local machine encryption tool. This means that files are encrypted before they are synced offline. This means any files so modified need to be decrypted before use. Obviously normal documents that need to be jointly edited on the web won't work that way (but of course this is what VPNs and Intranets are for).
Third, Geolocate
While Google Drive and related editing tools are compelling (esp. with 15gb free), it is important to use non-Google (non-US) resources. Yandex fills this need nicely. As well, though a US company, Amazon has many datacenters in countries other than the US, so their S3 and related services are pretty neat. Also, really like Linode. The only problem is that there is nothing useful from either in Hong Kong, a presence which is needed to get close to China, without being inside China (and still have the copyright laws of China).
Fourth, Splinter + Backup Everywhere
So the idea is that different kinds of media are in different clouds, but those cloud contents themselves have backups. For this, zipping up files into a few GBs and copying them to S3 can be super cheap (esp. if the backup S3 is in the same data center, and files are few and large, and then deleted after a limited rotation). For data that needs shared editing, go with Google Drive. They do encrypt data, but themselves have the keys (so hackers could presumably get the keys and decrypt, as well as the NSA/FBI can request your data). Yandex does not encrypt data, so that should be encrypted using Cryptomator.
Media Files
For large/misc. media files, such as tens of thousands of media files, go with Google Play Music (free backup and cloud player). They now allow uploads of 50,000 songs (previous limit was 20,000). This can't be beat. For the hundreds of GBs of video files, well that is still an issue. Even with the best Amazon Glacier option of $0.007 USD/GB that is still $7/mo for 1,000 GB. This is not close enough for free, as it still approximates the price of consumer-grade hardware for the same storage. In fact one can get 2TB external USB3 for the same yearly price.