This claim doesn't pass the sniff test, doesn't match a clear signal that anyone can see on graphs of data from Wuhan, NYC and Italy as well as other US states, and doesn't comport with our basic understanding of how infectious disease spreads. The fact that it's featured in a political website that uses the words "research... allegedly found" in its first sentence is just the cherry on top.
I don't really know how to answer your other objections. Their analysis looked at more countries than your list, your "sniff test" isn't a substitute for actual analysis, and the fact that a wide range of news websites summarised the results is to be expected (the actual report appears to have been sent to clients rather than posted on the web).
Here's a different source for you:
https://www.dailymail.co.uk/news/article-8347635/Lockdowns-f...
Taiwan and South Korea being random seems a spurious claim. Taiwan’s Vice President is an epidemiologist invested with a great deal of executive authority in dealing with public health crises and has guided the country’s response from the outset. South Korea was trending in a quite bad direction with the church outbreaks and quashed them through massive interventions in testing and mobile hospital capacity. And neither country has mass-scale lockdowns like the west (because they didn’t need them).
Other countries can invest in the same readiness. It's always a decision of limited resources and many opportunity costs (poverty, infrastructure, climate, security, etc).
Different countries with different experiences and difference cultures will make different decisions. That's ok, that's how it should work. Can't have it any other way in a democracy, right?
Sure, but both South Korea and Taiwan are wealthy liberal democracies. I know this isn’t your intention, but a lot of commentators seem to appeal to some kind of Western exceptionalism, completely refusing the examples of SE Asia democracies as a valid measure of comparison. To me, that seems like insanity, because again, they’re also wealthy liberal democracies and have had the best-in-class responses thus far.
https://dailycaller.com/2020/05/20/jp-morgan-infection-rates...
Sweden is about middle of the pack. Most of that is because of the virus getting into care homes, which a lockdown can't prevent anyway given the staff have to come and go, and blocking the elderly from all visits forever is deeply inhumane. Given their age many of them would rather catch the virus than live longer but always be alone, and have said so.
So far it appears lockdowns didn't affect the virus much at all. However, they are definitely killing people if you look at the changes in suicide rates, the backlogs for cancer treatment that have built up and so on.
The problem with believing that Taiwan and South Korea are doing better for fundamental reasons is that it may simply be random. Japan did very little or nothing, probably due to trying to avoid the Olympics getting cancelled, and had similarly good results. The differences in testing levels and definitions between countries alone make comparisons based on reported infection and death rates meaningless.