While I might agree with the sentiments but there's a lot of nuances that one must consider.
1. Almost all the countries you mentioned are quite homogenic ( I know there's 50 minorities in China and their total number would be more than 100 million along with quite a lot of differences between the hans itself like hakka but still). If not culturally then atleast they have a written language that unites 80-90% of the country ( phonetic pronounciation may vary). India's biggest spoken language is Hindi( which itself has too many variations like bhojpuri,maithili etc) doesn't even cover half the country despite the biggest two states UP Bihar lying in that region. Geographically it might span 30-40% at max.
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2. You are also forgetting the us help and aid many of these countries received( with the exception of China and maybe Singapore. Don't know about taiwan, you may tell me about the if usa helped taiwan)
3. And while these countries clearly industrialised while being authoritarian but there is a survivorship bias there. Plenty of countries in Africa being run by dictatorship, they aren't publishing world beating growth. Myanmar fell to military coup a few years ago, they aren't growing at 10% + rate are they. Number of SEA countries have had military coups ( thailand etc.) They aren't the powerhouse similar to sk, Japan etc. Portugal was until 1974 a dictatorship, there wages are extremely low and they arent a powerhouse due to their authoritarianism in western circles.
Plenty of coups and dictators in South America happened too( I know there was huge role of usa but besides that) and they weren't developed during those reigns..
All I am trying to say is governing a nation is complex and it's naive to just say that if we were to switch from one form to another we miraculously would develop.