One fairly high-profile (yet topical) example of this is the top flight of German Football. East German teams rarely even make the German Bundesliga[0], and my understanding is that there’s currently only one Eastern German team in the 20-team league.
0: https://www.theguardian.com/news/datablog/2014/oct/17/west-g...
Building up North Korea isn't hard, living in North Korea is hard.
The reason it's important to me to say so is that at some point, some actual people with actual (limited) resources, will have to devise a plan to make it all better, and then actually do the plan. That is a huge challenge that involves trade offs and hard decisions. And if you start with magical thinking, instead of extremely realistic reasoning, you're going to end up hurting a lot of people.
For political reasons, reunification would be inevitable. It has been the stated goal of politicians for decades.
For economical reasons, reunification would be devastating. South Korea is not exactly poor, but the amount it would take to lift North Korea to a living standard which is not outrageously low (let alone comparable to the South) would be immense, and the living standards of South would plummet very significantly. This is a totally different kind of deal than reunification of Germany.
For cultural reasons, reunification would be a tough cookie. Nearly 70 years apart, in strict isolation, and under a constant inescapable brainwashing made North Korean culture drastically different from Southern Korean. Even the language evolved differently (and totalitarian regimes are keen to control and bend the everyday language to match their narrative). Now North and South are not separated brothers but more like distant cousins who grew separated by an ocean.
So South Korea will try to keep North Korea going as much as possible without losing face.
Source: a few lectures by experts in the question.
The "kid" in the phrase "kid gloves" doesn't refer to children. It refers instead to leather made from kid goats. Kidskin leather is thinner and softer than other kinds of leather, and doesn't leave smudges on delicate articles. Hence the phrase "kid glove treatment", implying handling something with delicacy and tact.