Well that’s another part of the problem is when you ask how long have humans been on the earth you get a lot of vastly different answers depending on who your asking ranging from 60,000 years up to 800,000 years.
This is really a matter of what you consider to be modern humans including speech, higher reasoning, creative thought, etc. and when these arose. Most of these features are hard to track in the archeological or fossil record.
The lower age, 60000 years, is driven by the people of Australia who have the longest separation from the rest of humanity at 50-60,000 years. Since these peoples (Australians and non-Australians) both have the same basic, fundamental human characteristics the split must have occurred after those features developed. Therefore, our species is at least 60,000 years old.
The other end of the range is roughly the separation point between the Africans and the ancestors of the Eurasian Neanderthal and Denisovan populations. When Africans again left for Eurasia, there were successful matings that left small amounts of Neanderthal DNA in their Eurasian descendants. (There is, as I recall, some evidence that those Neanderthal/African hybrids may not have been fully fertile, indicating that Neanderthals and Africans were separate, but closely related, species. The debate continues...)
If Neanderthals are human, then humans have existed for nearly a million years. What we do know is that when their ancestors left Africa, our common ancestors were cooking food with fire and crafting cutting and scraping tools by chipping rocks. Could they make all of the sounds of our languages? could the develop the rich languages we have? Could they understand the inner workings of others thoughts as well as we do? I don't know. What ever non-appearance differences there were, they apparently did not inhibit attempts to mate.