But I don't think my argument applies to human intelligence, it just means that human intelligence is what you can get with all the data points you can get by observing the world (and some simulation done by our brains, but I'm under the impression that our brains don't perform accurate simulation, looks more like heuristics).
That's probably only a problem if it is must faster than everbody else.
> let alone faster than what happens in our environment
That is often not very hard. When a bottle rolls off the table, you can catch it by approximately predicting it's trajectory without computing the precise evolution of the ~10^26 atoms that make up the water bottle. Compression is a corner stone of intelligence. The second corner stone is using compression to choose actions that maximize expected cumulative future reward.