All the providers have a couple “tricks” they do to cut costs and restrict abuse.
First of all, if you are uploading a file that already exists on the system (detected by at least two strong hashing algorithms); they just keep a single copy of it and then use a pointer to it.
Second, if you try and upload hundreds of gigabytes of stuff they will very quickly throttle you in the hope that will just cancel the upload. They also won’t keep partial files.
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