If you think about it, it would be literally impossible for the DPRK to exist without the support of the people.
Their military budget is $6 billion, but a lot of this equipment is shit like nukes or missiles, that they can't use on civilians.
Their police is a lot more demilitarized than the US. Even if the military used guns, there is no way the military could prevent an uprising with a budget way smaller than the police of New York alone.

And even the assumption that the military would use guns on citizens is a pretty big one, their entire culture is centered around their love of the Korean people. There is no way the military would shoot civilians.

And even if they did, remember they liberated themselves from Japan through guerrilla warfare and fought a war against the US, beating them multiple times before being genocided entirely. They also know they would have the support of the rest of the world if they wanted to overthrow the state. If there was an uprising, the country would be over in a week.

Now you may say that there is a lot of propaganda, but then again, there is a shit ton of propaganda in the US, and people are still revolting.

And in the US people think they're free, in North Korea, the press is controlled by the state. If they lived in an oppressive dictatorship, don't you think they would have figured it out ? They're not dumb, they're not submissive ants, quite the opposite actually, have you ever seen an angry crowd there? You don't even need to debunk lies to realize that the imperialist narrative is false.