The virus spread quite well in Wuhan and the South Korean church though. Why do you dismiss the significant policy differences as a sufficient explanation?
There are 470 million people between those three Asian nations, and fewer deaths than in Canada (which has done a very sound job against the virus).
Indonesia has as many deaths as Sweden, with ~26 times the population. The Philippines has 1,846 deaths vs Brazil which has 82,771. Bangladesh has 2,751 deaths, 30% of what Germany has, despite Bangladesh having nearly twice as many people. The Germans responded in extraordinary fashion to the virus. Bangladesh has so few deaths because their response was vastly superior, better funded, better organized, technologically superior in its testing and tracing? Comeon.
The Philippines had an amazing response to the virus compared to Germany or Canada or Brazil or Switzerland? No way. There's definitely more going on there, including an impact from the different climates. It's entirely reasonable that some parts of Asia could have greater immune protection due to past virus exposures.
In the early days of the outbreak Vietnam didn't have rigorous contact tracing setup, so if a case turned out positive they simply shut down the entire neighborhood for two weeks. Once the source was mostly international cases, they also shut their borders and made no exceptions, not even for trading partners begging to let a handful of people in. But most importantly, even when case numbers went down into single digits, they kept up total lockdown for an additional two weeks.
This saved them from making the mistake Korea made in removing social distancing restrictions the day before a major 5 day weekend which seeded the country and we've been squashing spot fires here ever since.
Authoritarian regimes that have earned public trust through effective governance are probably the countries best suited to manage a pandemic like this one. It's just there are very few of them so it's hard to think of such countries as a category.
Also, South Korea's death numbers (and Vietnam's) both look pretty good compared to any nation in western Europe.
Most of my asian friends believe mask wearing and willingness to self isolate (sick, so stay home/wear mask/try not to spread) are a factor when comparing to western nations.
Vitamin D may also play a part. I recall there were studies indicating that Vitamin D deficiency could be a problem for those who get sick. I have no data here but I suspect westerners are far more likely to be Vitamin D deficient.
I would not be surprised as well if general health across populations has a relationship (diabetes, obesity etc).
Aside from that, regulation and enforcement matter. Australia kept cases under control early on but their recent delay in locking down hard with new cases has meant the spread continues out of control. New Zealand on the other hand had a very strong lockdown and try to enforce quarantine and case management. So far cases are controlled and limited only to those returning from overseas. Community spread was eliminated (to date).
It's obvious if you check the population pyramids (Google "population pyramid $COUNTRY_NAME"). Most of the deaths are in the older population, and the average population age of Vietnam, the Philippines and Indonesia is much younger than e.g. Canada.
> Indonesia has as many deaths as Sweden, with ~26 times the population.
Indonesia's deaths are still rising (about to pass 100/day), while Sweden's have tapered off (has been below 20/day for a month and is still dropping).
> Bangladesh has 2,751 deaths, 30% of what Germany has, despite Bangladesh having nearly twice as many people.
Similar here: Bangladesh's deaths are stable (not really increasing or decreasing) at around 40/day, while Germany has tapered off to like 5/day for a month (and recently had days with 0 deaths).
Philippines vs Brazil seems to have a pattern that supports what you're working from, though - deaths in the Philippines haven't really spiked (aside from two recent days, not yet enough to know if it's an outlier or not).
Take into account that beating this virus through contact tracing and isolation doesn't require having the fanciest tech. The actual steps are really simple.
Germany is wealthy enough that it doesn't have an infectious disease response "machine" on standby at every level, Bangladesh is not. Bangladeshi public health teams deal with outbreaks of deadly infectious disease all the time, that's not true in any wealthy country.
I don't doubt that if you gave each country five years, Germany would come up with a better funded, equipped (and maybe even trained) public health system but this was a situation where days mattered.