Ancient Greeks were not as advanced as modern-day countries are. Although they did invent and have an organized system of living, modern-day civilizations are ahead of our time. For example, in our world today, we are surrounded by the idea of technology. It has advanced so much over the past ten or so years. But, in Ancient Greece, they invented many things over a whole century- with some inventions not getting more advanced than they were originally thought of.
Hope this helped a little bit!