(though I'm not sure what such motivation would be)

I mostly mentioned motivation there in order to pre-emptively rule out the Douglas Adams dolphin argument: in case anyone tried to argue that some other species was more intelligent than us because they didn't build up a technological civilisation, or that they were intelligent enough to do what they wanted to get done and that was all that was important. The key test is whether they could have done what we did if they'd wanted to; if it were shown that they could have and they deliberately chose not to, then I'd concede the point.