Pretty sure a D9 bulldozer is bigger than a human, and an A380 and a tunnel boring machine and a steam engine and a crane, and the truck that picks up my rubish and....
It's telling us: we live in a material universe, intelligence is just a function of physical attributes. If you want to deny the possibility of machine intelligence, the burden of proof is on you because, denying that would be so ridiculous as denying supersized machines.
>2 It is worth clarifying that there are, of course, systems today that appear to exceed human size in narrow dimensions. Lamp posts are one example. The predictions that we are considering concern some more general notion of largeness.