I don't know or care much about the DPRK's political system. Other than blatantly sensationalist lies, I don't really see much reason to challenge anyone's read on it. I can't think of many practical questions that would be affected by the DPRK being democratic or not. I oppose US imperialism in the region regardless.

Stepping back from that, in general, no matter where you are in the world, it isn't hard to rig votes, which means a lot of legitimacy has to be derived not from principle, but from who you trust, subjectively. No matter what system you design, somebody has to count the votes. Obviously, election observers from the "international community" can't be trusted either. So like anybody can say they're doing a poll or a vote and announce whatever results they want and there's no reliable means of oversight if you don't trust the people doing the oversight - "Who watches the watchmen?"

I can speculate that Alan Dulles had JFK killed because his job was assassinating world leaders and he was fired shortly before it happened and he was on the investigative committee into his assassination (which was a clownshow), and from that I could argue that the US is a sham democracy controlled by the intelligence community. When people talk shit about the DPRK or many other countries, that's generally what they're doing. Replace Alan Dulles with Kim Jong Un, replace JFK with some rando, and make the evidence flimsier, and then say, "Oh, the CIA/Kim Jong Un can kill whoever he feels like without repercussion so it doesn't matter how supposedly democratic the system is, anyone who goes against the real power gets merked."

But the difference is, we don't have to rely on speculation and trust to know about a lot of the bad shit that the US is involved in. Neocolonialism, for instance. We can see as an objective fact that many countries had their resources violently seized during colonialism and that those resources were never given back. We can also see the restrictions that organizations like the IMF place on their domestic policies, written in ink. We can also see the stuff that the CIA has admitted to, whether it's Operation Condor, MKUltra, or whatever atrocity you prefer, because there's no shortage to choose from. More recently, the politicians and journalists we have are the exact same ones that lied us into the War on Terror which left millions dead - and none of them ever faced any consequences for it. Even if a dictator somewhere kills some dissidents to stay in power, it comes nowhere close to the mass death and suffering the US has caused. And if it turns out that the supposed "dictator" was democratically elected and the people he supposedly killed were alive the whole time, you know, that's cool too. But I don't see much reason to die on that hill either way.