The world was really jarring and weird, required a lot of suspension of disbelief.
In a world where you have motorcycles, the best assassins fight with swords ? Get the fuck out of here.
They have electricity, but no sniper rifles ?
You must go full post-apocalyptic or full SF, there is no such thing as a half-way apocalypse.
Maybe I remember it wrong, but from the first few episodes that I watched, I found this dissonance to be the main factor in quiting the show, for me.
The reason for no guns on the show was because it was a martial art focused program. The showrunner said that is what they wanted and just never gave a reason for there being no guns. If there were guns then everyone would be bitching about them using swords and martial arts.Knowledge could be lost. Granted gunpowder was adopted faster than any other tech in the history of mankind, but if your society was insulated enough and no one remembered how to make it, maybe?
They still have TNT
The show was cancelled so this is it, hopefully doesn't end on a cliffhanger.