Neanderthals have existed longer than Homo Sapiens have. You're assuming that the path we took is a normal and expected path. Why?

The way I see it, the path we took was very unlikely and most humans during the "cavemen era" did not agree to it considering we find evidence of "civilised" humans replacing and subsuming most hunter-gatherer human groups throughout the past 10k years, like how Middle-Eastern Neolithic farmers migrated to Europe and almost entirely replaced Western European Hunter-Gatherers and turned them into second-class citizens in the societies they created. Due to this, most biggest ancestral influence of Europeans comes from these Middle-Eastern farmers and not the indigenous Western European Hunter-Gatherers. These farmers were so influential, they're responsible for giving Europeans very pale skin (in comparison to the dark-skinned WEHG) and advanced (for its time) agriculture. And it wasn't just in Europe they did this, they also went into North-East Africa and Ethiopians/Somalis/Eritreans are about 40-60% Western Eurasian in genetic heritage.

If humans were more solitary like Neanderthals, then perhaps our agricultural and "civilised" ancestors would have stayed in small groups which would prevent civilisation that would could allow calculus to be discovered/invented (depending on your perspective of mathematics). But they didn't, they were known for having large tribes, large-scale migrations, trade routes that went across seas, tribal alliances to take over other human groups and then eventually agriculture and civilisation. I don't see this as part of what makes us intelligent because Neanderthals may have been as intelligent as us and yet they stayed in small groups and everything they made came from the local environment.

Also, Homo Erectus may not have been exactly as intelligent as we are, but they were still quite intelligent and they've existed far, far longer than we have with similar bodies that could allow tool-making and potentially language. They could still have come up with agriculture and civilisation and metal-working, but they didn't. Did they really not have enough time, or did they just not want to?

No, it's whether they even want to.

So should Neanderthals and Homo Erectus not exist to us?

Sounds like a chill vibe.

Yeah, that makes sense to me. Hence why need to look after this planet and take climate change seriously.

Except once again, we had Neanderthals and Homo Erectus who were close to or as intelligent as us, and we have no evidence of them being technologically advanced or contributing to science.

That would be very interesting, although how could we communicate with them? Would they even know we're here? Would we even know they're there?

Which comes back to colonialism and imperialism.

Do you think we're near the end of technological progress?

But then again, other human species had the potential and didn't take it, so why do we assume intelligent alien species would?

Could you send them forward? That sounds interesting but I'm assuming this is humans meeting aliens so Avatar is probably one example.

Or perhaps almost no other intelligent alien species go through this process of "civilisation". Consider other intelligent human species and how they didn't have an agricultural revolution or civilisation. If Homo Sapiens hadn't arisen, would we be a planet with no intelligent species?

Sure, but we're assuming there are any aliens who can travel to Earth.

And I agree that there must be intelligent alien species like us out there, but what I'm saying is perhaps they're just so rare, even rarer than Drake's Equation suggests because he didn't include what a species wants to do.

Did Neanderthals or Homo Erectus want to become a technologically advanced, "civilised" species? Did most hunter-gatherer humans choose this form of society or were they replaced or subsumed by human groups that did want to do this? Look at pre-historic Europe, Neolithic farmers were known for creating segregated societies and replacing entire areas with members of their own and leading to the near-extinction of Western European Hunter-Gatherers. And that's just one case. The Yamnaya people also replaced large parts of Europe. And that's just one small continent. This happened everywhere around the planet, but mainly with our species. If there weren't any groups of "civilised" humans or if those groups were defeated by hunter-gatherer humans, perhaps we'd be just like our ancestors were for 95% of our history.

Perhaps, intelligent aliens species just didn't go down the same path because they didn't want to.

That makes sense, but it doesn't seem like a good idea to assume alien species behave the same way we do.

I feel that's completely fair for us to think that way, but it doesn't seem like a good idea to think of intelligent aliens that way when not even other intelligent human species took the same path we did.