A big part is holding onto smart and valuable people or attracting them back home.
On this front China and Japan do much better. Japan is understandable due to heavy cultural allegiance which China honestly doesn't compare to Japan mostly due to Japan being more developed and wealthier. South Asian countries are much poorer than China and development is still at starting out levels in fact for most people it is too low. The basic level of development must first be strived for before any other thoughts about the next steps towards development.
Build sanitation, piped water, clean up cities, build decent accommodation. Start building cities or improving them to a level that begins holding onto second rate talents and then eventually first rate talents.
This is why it's ridiculous to imagine India getting anywhere in the next few decades. It has not really truly begun the ground works which take many decades to complete. India's development strategy appears to be using disproportionate resources to propel a top strata while being okay with ignoring literally more than 50% of their population. This is strategy for failure and will only produce pockets of top tier areas/talents/industries and nothing else plus nothing of true scale. As much as they talk about population dividend, all who promote that soundbite simply do not care to understand it thoroughly or benefit from misleading the stupid (which are the majority even in countries like China lol).
Clean up, sanitation, buildings, infrastructure, safety, stability, hold onto third rate talent, then second rate, then first rate and promote industry as you go along. On this, as much as India focuses more on top strata while ignoring majority, they are still doing better than Pakistan! I do not like this for one of China's strategic allies. I am not trying to hurt people's feelings but Indians are at greater level than Pakistan with this even if it's limited to maybe only the top 20% of their society if not still less. They have in the last twenty years started building for the top players to do something to lift their bottom but they aren't lifting their bottom and that's a distribution problem for them to deal with. Suffering and India go hand in hand not simply because of others (UK) but they are themselves unkind to their own bottom strata. China had similar problems until bottom strata stood up against internal enemies abusing that system and thankfully (for the nation of China) had a revolution to change things. India will not because their people's tolerance for suffering in this regard is actually higher than Chinese. I suppose certain aspects of their religion assist on this.
So many things to do that will take many decades just to get on the path of middle income country. Meanwhile the preferred action of some seem to be excuse making, attack others, make ridiculous soundbites and expect quick solutions. I do not believe South Asia will even approach middle income status until people get real and stop talking down on others and just mouthing all day rather than actually working. Again there will be ones here thinking well **** China you guys just copied paste and stole everything... to that it is exactly what I talked about above. Stay in denial and stay in delusion to those (not you guys but readers/others). The caravan moves on.