It's ridiculous to say that North Korea's economy is doing well lately

Luxury-filled Pyongyang Department Stores... The light and shadow of the North Korean economy amid a boom in foreign currency earnings
YTN
Foreign media analysis suggests that while North Korea is enjoying an unprecedented boom in foreign currency earnings through close ties with Russia—including the deployment of troops to Ukraine and the export of military supplies—there are limits to whether this will lead to a fundamental improvement in the economic structure. According to major foreign media outlets such as the UK's Financial Times (FT), high-rise buildings have recently appeared in downtown Pyongyang...
The wealth gained through the Russia-Ukraine war is being distributed to the Pyongyang establishment,
It is not being used for national industrial development like South Korea during its industrialization period.
They aren't even distributing it evenly to the provinces...