It's difficult to know exactly what it was like. It clearly was capable of fulfilling its desires and had advanced culture and magitech whose descriptions sound like technologies we ourselves invented. We only have a few snippets, but they show that their society was much more magic and nature oriented than ours, making it difficult to compare how "advanced" we and they are ... down different paths.
To further muddle things, Travelling changes all the rules. Weaving in general makes it very difficult to say who was more "advanced", because they're not constrained by the same physical laws as us in any fashion. If you can throw out Conservation of Energy, you can do unimaginably advanced things.
Further, although there's been confirmation that this is a different world/'verse than ours, the descriptions of ancient artifacts/stories in Tanicho ("mosk and merk fighting in the sky with spears of fire") sound bizarrely like veiled, allusions to an alternate earthour own recent past or future, complicate matters, because it shows how little we know about each others' capabilities. While they can open holes in the air and throw fire, we invented guns, planes, and (where Russiarunning water. They even show technological incompatibility with the previous age, because Nynaeve is able to heal things that the great medical geniuses of the previous age couldn't, even though they had all of these marvels and medical knowledge of their own.
My personal bias is that the USA cameAge of Legends was at a "comparable" level of technology to blows)our own Industrial Revolution, but on a completely unrelated track. Some of the accumulated arrogance of the Forsaken as to the backwardness and barbarism of the current time could be understood to be a mindset similar to ours during that period of advancement and experimentation and discovery. Or it could be that they're EEEEEEEEEEEVIL.