Every ancient society has things that they did really well. Some of the ancient Greeks were amazing philosophers. The Romans were titans of engineering. The civilizations in the East were amazing artists and philosophers as well. We are too proud to think that things are so much better today than they were in these societies.
Yes, many ancient civilizations were a lot more sophisticated and advanced than we realize. Many old civilizations developed great ideas, did amazing works, and were extremely organized and advanced. But their records weren't preserved, or they never even kept records. Or if they did keep records of their advances, we may not even be able to decipher them. So we don't know what they were like, and I feel they were far more advanced than we know.
The seal is composed of gold of 95% purity, has a mass of 108.729 grams and is designated as a National Treasure of Japan. Those factors, alone, arise the possibility that ancient civilizations were highly sophisticated.
The seal was reportedly rediscovered on April 12, 1784 and was found surrounded by stones forming a box-like structure around it. Being found is magnificent condition and is so beautifully constructed this topic deserves some of your research time.
We underestimate how sophisticated ancients societies were because they did not have many of the same modern convinces that we take for granted. But some of these societies accomplished things that we would never be able to do, like build pyramids without major hydraulics or other large machinery that we have.