Yeah but pi digits are essentially random noise, but any human is a precisely build system. E.g. there are exactly two identical eyes with nerves going to this precise area of brain, every time.

It's more like mega-efficient archive utility that unzips a few GB into a human, I just can't fathom it.

That's exactly the wrong way to think about it, and I'm surprised that so many devs think of it that way. We already have programs that works exactly like that (i.e. producing rich, complex output that would be many times the size of the input code + data if encoded raw): procedural generators. It's emergent complexity, not compression.