What the heck are you storing that you've used 20-30TB? I don't really get it.
UHD Movies? Why would you save those in the age of streaming? Family pictures/videos? At 20TB, you must have hundreds of thousands of pictures. There's not enough time in your life to look at all those! The only thing I can think of is that you shoot photo/video professionally, or maybe do some kind of 3D/video rendering?
But I agree with you - when you have this much data, why the hell are you transferring it to the cloud? Buy a couple harddrives, load them up, and stick them in a safe.