Magic and advanced technology are incompatible.
Before you go ranting at me, think about it. Have you ever read a good story where they have both magic and advanced technology? No? (if you have, please point it out to me) Thought so.
That is because, as I said, magic and advanced technology are incompatible. You get either one or the other. Not because the universe implodes if you mix them, but because they are, in a way, essentially the same.
Magic, not necessarily very strong, cancels out technology. The mental dicipline and prowess needed to do magic rules out the physical, mechanical skill needed to make machines as advnaced as the ones we have today. Of course, you can have a little of both, but the resulting steampunk-esque universe can easily go horribly wrong unless you set down clear, unbreakable rules from the very beginning, and even then it's just weird.
Magical societies don't need advanced technologies because they have magic. Magic to heal, which means they don't need advanced medicine. Magic to make war, which means they don't need advanced war machines. Magic to build and transport, which means they don't need cars or trains or skycranes. Perhaps even magic to open portals, which eliminates the need for space travel.
Technologically advanced societies are advanced because they haven't had magic. They have had to develop medicine, war machines, airplanes, submarines, spaceships, cars, trains and all that stuff. It has been necessary for them, because they have had no other way to advance.
Please, do note that I'm only talking about tech levels here. The cultural advancement is a subject I leave alone.
Listening to: The High Kings
Reading: Good Omens
Watching: LotR Trilogy- Extended Edition
Playing: Mass Effect 2