I'm talking about the modern age after it got ruined after WWII. It recovered like Western Europe but faster and more impressively, becoming the 3rd largest economy on Earth and pioneering all sorts of technology along with South Korea.
Yes it's small, but a wonder of capitalism nonetheless. This one rock off the Malay peninsula has a GDP greater than most American states, and most countries for that matter. Thanks to the entrepreneurial leadership of Lee Kwan Yew first and foremost this was able to happen, where this tiny bit of land, without any natural resources, managed to develop and establish so much wealth on itself. The aid they got was minimal in terms of the big picture; the money that they got was mostly an investment because of how much Singapore had going for it.
(You didn't address this so moving on).
Blatantly false, plus you have no qualms about North Korea doing the same so whatever. South Korea amassed its wealth like Japan did; through a strong, central government that attracted investments in various industries, particularly ones it led like electronics and other technology. North Korea stagnated after a while because their system is only good for building basic architecture but South Korea continues to thrive to this day. Yes it has problems, and yes it's not a utopia, but it's remarkably wealthy and advanced for such a small country; truly a wonder of capitalism and a testament to human ingenuity and hard work.
Not to mention, socialist countries aren't that cool for developing quickly. They just took on previously-established technologies and methodologies, then made their people work like hell, and eventually did indeed end up with a part of their country industrialized… though not even to the same level of the West, and of course they had other problems too like frequent shortages of common things.