In this case they're pretty far along that road, though. It seems unlikely they'd evolve away from a very similar brain structure or hand structure to us, for example.
This implies that our brain and hand structure are the most crucial characteristics. There's been endless claims in the scientific literature about this or that physical feature or behavior, but it's all extremely speculative and lacking in both evidence and theoretical power.
We can't even clearly articulate what distinguishes human faculties or behavior. Every time someone proposes a definition (e.g. tool use) and then tries to collect evidence (e.g. opposable thumbs, abstract modeling, etc), the definition falls apart as people identify analogous faculties, behavior, and capabilities elsewhere. I think it's self-evident that human faculties and behavior have a fundamentally and categorically superior characteristic. Others think that our failure to so far find it suggests that it doesn't exist. (Not sure how to square that with reality beyond simply suggesting that human civilization is purely and continuously accidental, or perhaps that a constructed spacefaring capability isn't meaningfully different from other behaviors.) Either way, we're still rather ignorant about what we are. And even if we could articulate it, we'd still need to understand why and how human evolution unfolded as it did as there may be a filter (https://en.wikipedia.org/wiki/Great_Filter) making convergent evolution of human-like intelligence unlikely even if evolution were directed somehow. So we can't meaningfully say anything about how "far along" chimpanzees or any other species might be.
We can't even clearly articulate what distinguishes human faculties or behavior. Every time someone proposes a definition (e.g. tool use) and then tries to collect evidence (e.g. opposable thumbs, abstract modeling, etc), the definition falls apart as people identify analogous faculties, behavior, and capabilities elsewhere. I think it's self-evident that human faculties and behavior have a fundamentally and categorically superior characteristic. Others think that our failure to so far find it suggests that it doesn't exist. (Not sure how to square that with reality beyond simply suggesting that human civilization is purely and continuously accidental, or perhaps that a constructed spacefaring capability isn't meaningfully different from other behaviors.) Either way, we're still rather ignorant about what we are. And even if we could articulate it, we'd still need to understand why and how human evolution unfolded as it did as there may be a filter (https://en.wikipedia.org/wiki/Great_Filter) making convergent evolution of human-like intelligence unlikely even if evolution were directed somehow. So we can't meaningfully say anything about how "far along" chimpanzees or any other species might be.