The Problem with Reinforced Concrete
newsroom.unsw.edu.au
newsroom.unsw.edu.au
Although, stainless is not rust free, it's called stain-less, not stain-free. So it will degrade eventually especially in harsh environments.
Others, like Hastalloy and Ferrallium, have very good resistance to corrosion. A company I worked for used these metals for burial containers that were certified for ~300 years.