Most of what I believe is from statements made by people who escaped North Korea

Those come from people who are taking money from NIS (formerly known as the KCIA but they changed the name to make it less obvious it's an occupied state). Those people are contractually obliged to paint the picture that South Korea wants in exchange for that money.

Anyone that does not take that money is politically persecuted, prevented from leaving the country, and monitored constantly.

The very fact that you use the word "escaped" is itself nonsense. Tens of thousands of DPRK citizens work outside the DPRK. The border with China is also an open border with tonnes of people travelling over it every day trading black market goods back and forth. The picture of "escape" that is painted is a myth created by the heavily militarised southern border, it does not exist on the northern borders.

Putting aside the word "escape", have you considered listening to the statements of people who have left the country who did not take money from the NIS? You should watch this whole video but particularly the guy in the middle. https://youtu.be/3V4Hnl7J9H4?t=678

I know someone who has left China because of political prosecution

That is very vague. Persecution for what exactly? I do not oppose all forms of political persecution. I actually think you'll agree with me when I say that the half of americans current supporting reactionary politics will actually require political persecution in order to make it a better country. So what exactly was this person being persecuted for? And what exactly did this persecution manifest as? Details matter. If it's one of the HK riots lot, they got handled very lightly compared to what the west would've done to them.

I don't listen to what most Cuban refugees have to say about Cuba, same applies here.