The only reason why we can't out sentient protons folded out of 28 microdimensions into our 3 macrodimensions is the same reason we can't rule out that our universe is actually the works of a giant hand puppet player called Zquaarx.

The problem is just - if any of what happens in 3BP was to actually happen, we would not have to be a little wrong (like Newton was in regard to celestial mechanics) but so wrong that it doesn't even make sense to apply what we know at all.

This is, by the way, the exact point of the first part of the first book: physicists discover that all off the known physics are completely wrong.