Before seeing this page, I had always assumed that PIE was a lot older. It’s amazing how much linguistic development has occurred in ~6,500 years!
Now that we have so much written language from the past, won't that have a sort of fossilizing effect on the language? For example, prior to writing systems, people had no idea how their ancestors communicated. Now with written text and audio recordings, we know in great detail how our language used to be used.