These "billions" are conjectural based on limited analysis of early minded blocks with no-to-little connection to Satoshi, FWIW. Essentially there are a set of early blocks which have never been spent whos structure indicated non-standard software was used to mine them. People assume Satoshi because that's the exciting thing to assume, and it isn't like anyone else who mined a lot of Bitcoin early on is becoming increasingly eager to self-identify and potentially get themselves targeted for kidnapping. The pattern started a couple weeks after Bitcoin started and continued until it had mined on the order of 16k blocks.
Sometimes people use figures which are dramatically higher which come from counting literally every block in the first year which is unspent, not just ones matching that pattern. That is provably a radical overestimate, as it includes blocks mined by varrious known parties. A common characterisic of almost all musing about Satoshi is extensive confirmation bias e.g. "Satoshi was an early Bitcoin user thus any early Bitcoin user is satoshi!".
In any case, regardless of who Satoshi is/was, wouldn't you like to live in the timeline where some early Bitcoin fortune was used to fund turning cryonics into something that works? Hal is cryogenically preserved, so maybe he's not dead-- only resting [1]. :)
I think the idea that someone managed to get cryonic recovery working specifically because they believed doing so would get them access to a Bitcoin fortune would make for an amusing science fiction novel. ... and really, Science Fiction would be an aspirational level of rigor for most speculation about the identity of Bitcoin's creator. Fortunately, Bitcoin was designed so that it hopefully doesn't matter who created it.
[1] https://old.reddit.com/r/Bitcoin/comments/2evdr8/hal_finney_...