I wonder if progressively shrinking the scale from human-visible to as small as we like would be a better way. After people see the obvious data, it would be clear that there's always more just out of sight and create the incentive to develop the technology to access it.

Stainless steel still corrodes, and even 316 can't even be used for many marine applications because of the salt water corroding it. Maybe fancier alloys are OK but for 1000s of years, it might pay to use something more history-tested.