We have to give them credit for holding society together, but it must be kept in mind that human civilization has been lessening since the War of Power - the White Tower has always been in a position where it's influence has been receding as humanity dwindles. With Tarmon Gaidon around the corner, it is a fragment of it's former self, and even in the greatest days of the White Tower, the feats and successes of it's Aes Sedai paled in comparison to those of the full assembly of Servants during the Age of Legends.

Even though it is easy to think that the Third Age is a healthy state of existence, all evidence indicates that this is a world where humanity is in a decline and one which never fully recovered from the apocalyptic events of the War of Power and the Breaking. There are vast swaths of the globe that are completely uninhabitable, and others still which are wretched (Shara and the Isle of Madmen, for example). Perhaps with saidin cleansed and purified, true healing can start happening.