The worst thing about iCloud Drive is that almost everything you have there is downloaded to whatever computer you're using. If you had 40 GB of documents in iCloud, they would also take up 40 GBof space on your computer.
Apple defended this setup by saying that iCloud (unlike Google Drive) was for backup, not saving space on your hard drive.
Well, Apple has finally wised up. On Monday at WWDC, Apple announced optimized storage. The system will now automatically store stuff you don't need on the cloud, freeing up space on your hard drive.
For instance it could take this hard drive with 20 GB free:
Apple
And free up another 130gb:
Apple