“But somehow the royalty listened to this guy and not the experts.”
He was turned down by royalty in multiple countries multiple times based on the advice of their experts. After years of pleading, King Ferdinand agreed to funding but it was not provided by the King directly but as part of a debt relief package.
I have always wondered if C.C. was the first guy (Captain of ships) to try the crossing. My guess is that he wouldn’t have gotten three ships if there wasn’t some previous intel about the possibility. Plus, he was just the first guy to “get back”.
The “Mississippian culture” as well as a few others fell apart around the early/mid 1400s. Some say it was due to overuse of the land - but the Mississippians were on a flood plain and had been successful for 500 years or so.
My guess it was due to disease that they could not handle and the accompanying panic of a plague. You don’t have to actually get back to Europe to deliver a plague - you don’t even have to be alive when you get to the Americas for that purpose. There was (verified) a large amount of trade via waterways by indigenous peoples, well prior to the “discovery” of America.