How could the snowball of smartness that happened to us be reproduced with other animals? Is there any evidence to suggest that the non human apes have gotten more intelligent since we split? What conditions would they need?

Gibbons can walk bipedally very well and yet they aren't even as smart as the great apes, dolphins or elephants. Dolphins are pretty much doomed since they don't have a way to make tools, and elephants might have a chance with their trunks.

Apparently, Oreopithecus, another species of ape that wasn't directly related to us, was also bipedal, and dexterous with its hands. And yet they amounted to nothing
https://en.wikipedia.org/wiki/Oreopithecus