I will agree with Chris G. about one thing. The U.S. is no worse than much of W. Europe in regards to deaths, which is a better indicator than confirmed cases. Worse than Germany, and worse than most of Scandinavia, but no worse than the UK, France, Spain, Italy, Sweden, Belgium, and the Netherlands. Why are these Western democracies faring so badly compared to much of the rest of the world?
I think one factor, which we've discussed here before, is that Westerners are more. resistant to obeying central commands that restrict their freedoms. In the U.S., as we've all seen, there's been a huge movement against lockdowns. Where I'm at, people don't have any choice. What the government says, goes. Because of my age, I'm literally not allowed outside my home AT ALL (presumably, there would be an exception to go to a hospital), and people under 21 are similarly restricted. Everyone else can go out, but only three times a week, the days specified on a pass we all get.
But a second factor has to do with transmission of the virus. As I've pointed out here before, there is a very strong correlation between population density and case rate in the U.S. The highest rates of cases and deaths have generally occurred in the cities and states with the highest population densities. You would think a third world country would be subject to this same effect. Manila reportedly has the highest PD of any city in the world. It does have a fairly high death rate, about 450/million, but that isn't as high as the rate in many less dense American cities, e.g., not only NYC, but Newark, Philadelphia, Chicago, Boston, Detroit, New Orleans, Seattle, Minneapolis-St. Paul, Long Beach, Riverside...
Why not? The sheer density of population only matters to the extent that people interact with each other. In the West, people have large numbers of interactions with others, at work, on public transportation, in malls, restaurants, and stores, and so on. These kinds of interactions certainly occur in Manila, but to a lesser degree. The great majority of people are somewhat isolated in poor areas of the city (that make American slums and ghettoes look like a millionaire's row), and can't afford to mix with others on a regular basis. They may ride public transportation (jeepneys, which carry far fewer people than busses and subways, and are open to the air, so any viral aerosol tends to be dispersed quickly--and they're all shut down now, anyway), go to the mall (but not often, and not being able to buy anything, they don't stay there long), and eat out (at cheap eateries that are mostly outside).
And once you get outside of Manila, the isolation increases. A large majority of the population lives in rural provinces, in villages or more remote areas. The density of these areas is much less, and probably even more important, there is relatively little contact between their inhabitants and the outside world. So you don't see so much seeding that occurs in the West, where people frequently travel from one country or one state to a rural area, thereby spreading the virus. This is far less likely to happen in a third world country.