It might be helpful to distinguish between technical knowledge, and commentary on the human condition. Technical knowledge has obviously changed dramatically, making the ancients less useful commentators on that subject. But the fundamental human condition has not changed in thousands of years, so they were as qualified to discuss this as we are.
The fundamental human condition is very important, because that’s what drives what we do with the technical knowledge.
I agree with the comments above regarding the ancient’s relationship with nature. They were more in touch with the real world than we are on average, because they didn’t have so many symbolic distractions. They had a strong relationship with nature, whereas we are more likely to have a strong relationship with ideas about nature.
Another issue is that ancient writing had centuries to mature. A lot of the junk writing in ancient times has presumably been discarded along the way by succeeding generations, generating a higher signal to noise ratio than is possible in modern times when so much of what we are discussing now was thought and written quite recently.