How well are developing nations handling the COVID outbreak?

There has been some discussion recently about the risk of terrible COVID-19 outbreaks happening in the developing world, where public health budgets are much smaller. This is happening in Ecuador right now.

However, I noticed that a lot of the countries that seem to be doing particularly well at handling COVID are not the wealthiest ones. In Europe, Czechia, Slovakia, Bulgaria, Greece are among the poorest in Europe but have been doing better than their wealthier neighbours. Vietnam is an example of a very poor country that has nonetheless done a great job of keeping their caseload down. These are just anecdotes though.

To address this systematically, I think test:case ratio is a good measure of how well a country is doing in the pandemic -- if a lot of tests are being done for each positive case, it generally means that people can get tested at the first sign of symptoms, and their contacts can get tested as well. Countries with high test:case ratios tend to be looking at declining caseloads.

I graphed out test:case ratio vs per capita GDP, and they're barely correlated -- in fact it suggests that poorer nations are doing slightly better on their test:case ratios. This is true whether I use nominal per capita GDP or PPP.
Is this a fair way of measuring this? If it's true, what happened?

Some ideas:

• Did poorer nations have outbreaks later because they have less inbound international travel, so they had more of a chance to ramp up on knowledge and testing capacity first?
• Are more of these nations equatorial or in the southern hemisphere, so they get a slight benefit right now from increased UV rays?
• Are poorer nations more used to scrounging and doing quick-and-dirty measures without a lot of bureaucracy and oversight. and thus are faster to respond in a crisis?
• Are poorer countries more used to dealing with serious disruptions of all kinds, making them less brittle than the tight low-margin systems in developed countries?
• Can poorer nations more quickly stand up a labor force of contact tracers?
• Are citizens of rich countries too used to not taking pandemics seriously because they think they have good medical systems to protect them, whereas poor countries are used to the experience of having to combat various epidemics?
• Are we getting unreliable data from poor nations?
• Are some countries omitted from the records because there's no data from them at all?