I said human architecture - so human like ability to solve general problems sped up without the other human constraints (like needing to eat) and focused on solving a problem. It isn't like a billion independent humans just doing random things - maybe if they could all focus and coordinate on a single goal but the communication overhead from that would still make it different in addition to the other biological constraints.
You may not need that much access to the world to learn/infer a lot about it [1] and if a superintelligent AI needed access to more in order to achieve its goal it'd probably be able to get it.
[1] https://www.lesswrong.com/posts/5wMcKNAwB6X4mp9og/that-alien...
Maybe a single human, but can you run an entire world civilization and it's environment (basically Earth) in a sped up manner? Because one super fast human-level intelligence is still constrained in a way that all of civilization is not. What is one human sped up a billion times? Is that 1 billion humans? We already have several of those units operating around the clock. And those units have access to the world's resources, whereas one sped-up mind will not, unless it can gain control of the world.