What Technological Era would Runeterra be in?
And yes, I know. Its hard to place a technological era on a society that is semi-ruled on magic. I was looking at all the various pictures and art that we get of various cities. For what I've seen or read, they must be decently far into tech, but its weird that the world doesn't seem to entirely evolve with it. If you've ever seen the cities of Demacia or Noxus, you'll notice they have a very medieval feel to them; they're both walled in cities with the castle towards the middle of the complex. However, if you go over to Piltover and Zaun, you see a different type of city; Piltover is similar to England, mostly consisting of town houses where its denizens live. If you go to the underground of Zaun, its almost akin to the appearance of cities from the Bioshock series.
But what intrigued me most is the cinematic released by Riot for the new Star Guardians. If you watch it, you'll notice that Valoran City is mostly composed of skyscrapers, which means that at the very least, their technology is roughly where most of Earth is currently at. We've also seen our fair share of military progress; We know from Riven's lore that Noxus has developed biological weaponry akin to things we've used in previous wars. Jinx uses a machine gun and a freaking rocket launcher as her main weapons, then you have Corki who is flying in something almost akin to a helicopter, and then you have people like Camille and Viktor that are practically cyborgs.
And yes, I know what your thinking: They could be using magic to hold up these structures, and the weapons could be magically imbued. But from what I've read and seen, in terms of using magic to strengthen things, there was only one reference, which is the bridge built in Howling Abyss. According to Ornn, if they would have never enchanted it, the bridge would have lasted WAY longer. Which means, that given time, magic seems to wear off or even damage structures.