The Silurian Hypothesis

https://www.discovermagazine.com/the-sciences/what-if-we-arent-the-first-advanced-civilization-on-earth 

I've been intrigued by this idea since I was a kid.  Given the age of the Earth, I'm curious how long it would take for all easily findable evidence of an advanced (by our terms) civilization to disappear?  Would ten million years do it?  Or ten times that amount?