I am also aware of tanks that hold caustic soda. 75 years old. Again, minimal wall degradation. I know personally. I was personally involved in the testing. As with the other.
That whole argument is bogus. Most of the piping will be PVC. The portions that use stainless steel are relatively small. Pumps for salt water are mostly plastics these days. The hypothesized cathodic leaching is nonsense.
Consider the salt water reefing community has the ability to grow many corals that are very sensitive to metals with leaching metals being very low on the list of water parameters they have to pay attention to.