Even after months, many players continue to complain that "buildings from previous ages have no meaning" because it's still unclear how they function. This seems to be another UI issue—nowhere in the interface does it clearly indicate that these buildings still provide yield. As a result, the game keeps receiving criticism for something that isn’t actually true, but players simply can't figure out on their own (because it's not reported clearly).
Also, do buildings form previous ages cost maintenance or not? Does it change compared to previous ages?