You would think, but often things fail in unexpected ways.
https://en.wikipedia.org/wiki/Zinc_pest is destroying thousands of die-cast zinc-alloy toys from the 1930s to 1950s. Zinc alloys are pretty corrosion-resistant, so this was a surprise.
https://en.wikipedia.org/wiki/Cellulose_acetate_film#Decay_a... is destroying a lot of historically important documents in libraries that were laminated in acetate during the 1930s to 1950s in order to preserve them.
But this kind of thing sometimes happens to architectural materials, too.
https://es.wikipedia.org/wiki/Aluminosis is destroying a lot of buildings in Spain in the 1960s and 1970s. I've seen a similar process underway in buildings built during the same period in Montevideo, Uruguay, but I don't know if it's from the same cause.
https://en.wikipedia.org/wiki/Serpentinite#Serpentinite_reac... will destroy stone walls pretty quickly if you build them out of olivine-rich rock.
Reinforced concrete, especially in chloride-rich environments, will eventually spall from oxidation of the reinforcing minerals. Some kinds of aggregate, like dolomite, although resistant to weathering themselves, also have a tendency to slowly destroy concrete.
You can definitely build a wall that will last thousands of years in the absence of earthquakes, war, gray goo, or acid rain, if you make the wall out of quartz-rich or otherwise slow-weathering, low-TCE rocks like granite, cement it with lime cement instead of Portland cement, don't try to reinforce it, and don't make it too long, thin, and straight, in order to reduce thermal-cycling stresses.
Most of us would never think of most of those issues when we tried to overengineer.
The Roman aqueducts have some other interesting virtues, though: due to the arch, they used very little material. We could probably do better with stainless steel today, but they did pretty darn well with masonry. I don't know if you've ever tried building a masonry arch, but there are some nonobvious considerations, and a mistake can kill you.
