Storing data for decades or even centuries is a difficult thing. But the problem isn’t the storage it’s the data format!
Who knows if a person 300 years from now has a program that can open .png or .jpg? Or the dreaded .doc and .xls that even Microsoft has problems with today. This poor future fellow probably won’t have the capatibilities and might need a few years or decades to develop a reader app.
It only needs two ports and two docks. One of each at each end of the shipping route.
Do you really think building and maintaining thousands of miles of roads and rails is cheaper than a few ports?