Back-of-a-napkin math, renting enough disk space to store 10PiB of data would cost tens of thousands of EUR a month.
And if the threat actor used their own infrastructure, who are they if they can store 10PiB of data for months on end? Have you seen the prices of hard drives recently? 👀
This is not Snowden walking out of the NSA with a thumbdrive. This is a sustained, long-term, well-resourced campaign.
Talking about "a hacker" in this context is ridiculous.