How often does your cloud storage provider allows you to send 1Gbps to them ? For the ones I use (dropbox, mega, google drive), the answer is never where I live. At best, it will be 10% of that, and usually less.
Raising upload speeds would also give an incentive to cloud storage providers to take advantage of them and improve their ingestion speeds.
From a decent VPS I have easily hit 1 Gbps with google, Dropbox and OneDrive with rclone configured well.