What is the technology level in the Naruto universe? I think I will poke a plot inconsistency here.

Since the first chapter, you can see Naruto using what seems to be plastic googles, his clothes are made of seems to be synthetic fiber clothes. You can see that the village have video tapes (which also suggest the knowledge of electricity) and radios. They know the internal combustion engine, going by the mission to protect the bridge designer, in which they prefer not using the engine because it makes noise.

But later, or more like in all the plot, there seems to be instances where this technology could be used, like sending messages between villages/members, or setting up vigilance, but are not used.

Why is that?
Here's an extract of Kishimoto's interview


  Konohagakure no Sato Guns and vehicles shouldn't be drawn.
  
  A: Well, well, we reach the final keyword. The main stage of "Naruto", "Konohagakure no Sato". To you, what image do you have of this
  place? For example, was it modeled on the scenery around your parents'
  home in Okayama?
  
  Masashi Kishimoto: That's right. To be honest, I didn't think much about this, and got
  a lot on my inspiration there. Maybe it was subconsciously modeled on
  Okayama's scenery.
  
  A: What kind of time period did you set it in? If it was in the distant past, then covenience stores wouldn't be there...
  
  Masashi Kishimoto: It's not really any different to present-time. Though possibly a
  little in the past, maybe?
  
  A: What kind of place is it? Is it Japan? If so, what prefecture...?
  
  Masashi Kishimoto: It's a completely original place. I didn't set it anywhere. A place
  inside my own head... If anything, the climate and topography resemble
  that around Kyoto. As I've never been to Kyoto, it's my own image of
  it. (laugh)
  
  A: What material did you use for it?
  
  Masashi Kishimoto: I like Japanese culture, and since I studied it, I used a lot of
  material from that. Crests and folding fans... I often look at
  Japanese-style gardens and watch Kabuki.
  
  A: Do you have any rules about what is definitely not allowed to be drawn in the "Naruto" world?
  
  Masashi Kishimoto: Firstly, projectile weapons such as guns aren't allowed. (The one
  exception is Inari's bowgun.) Guns aren't suited to ninja. Gunpowder
  is used in the anime, though I don't think it should be there. And,
  vehicles such as aeroplanes are not allowed. I try to restrain
  technology that can be used for war... For example, if missiles were
  in it, it'd be the end. (laughs)
  
  A: Well, thank you very much for everything today.
  
  Masashi Kishimoto: Thank you very much!


And from Shonen Jump


  Shonen Jump:Your work seems to have a science fiction influence.
  Approximately speaking what is the technology level in the world of
  Naruto?
  
  Masashi Kishimoto: Actually, the world of Naruto doesn’t differ very
  much from our present time. TV, refrigerators and air conditioners
  exist in the world. The only exceptions are weapons and explosives,
  which I’ve decided to set in a much earlier era. That’s why you don’t
  see firearms.