Transportation, don't you think ninjas running and jumping all over the branches of trees is cool? And cars, trains, and even airplanes, aren't those pretty restrictive to ninjutsu practice? At most, horses appeared in Yukihime no Ninjutsu, and carriages appeared in the plot, so the notion of cars at all is a rationalization for the world as a whole.
Weapons, you can notice that there are no firearms in Naruto, it's all bladed weapons, even the samurai have long swords, that has to be, isn't that what manga fans want to see, intense physical confrontations, exciting ninjutsu duels? If you take guns, cannons and even missiles, is it still a ninja chapter? It's like modern warfare.
There are also some things are quite amusing, like the projector and so on, the old camera have appeared, proving that in general the world of "Naruto" is still technological water backward, but then there are some more strange existence, such as our society in recent times only appeared in the washing machine, air conditioning, but the general thing is still relatively backward, and also belongs to the era of the Cold Weapons.