I would say that modern engineers are more advantaged and benefit from their infinite access to knowledge and advanced technologies, therefore they can make structures that one could only imagine in the past. In the modern world, if say I am an architect, I do not even need to design a building. I just search the internet for plan drawings and put my name on them and no one will know they are not mine (Just emphasizing how advanced technology and access to knowledge have made things much easier). I am sure if the ancient engineers would have cracked these modern technologies with time. In fact, some of the modern technologies were developed by ancient scientists. Da Vinci's drawings on aerodynamics, bridges, load bearing walls, war artillery are the ones used to make modern war equipment, aero planes, suspension bridges etc. Da Vinci studied the human anatomy his drawings are used in modern medicine, making of robots etc. His drawings were so accurate and detailed and at that time, the electron microscope had not even been invented yet his drawings/developments from his drawings are the ones mostly used today. Therefore, to a certain degree, modern technology is dependent on past inventions.