I travelled through the Andes, Amazon rainforest etc... and while it was amazing overall, I wasn't impressed with Machu Pichu. There are way older and better built things all over Asia and Europe.
Your opinion is valid but in this case because isolated societies developed independently, the “oldness” is somehow relative.
My opinion is that MP exceeded my expecations. So did Taj Majal. It’s just something in our personalities.