I say that because Sweeden went from large infections/death per capita to a sudden drop to nearly nothing, almost instantly. We saw this in NY as well, and they didn't change their lockdown policies much. In fact, they loosened them as the numbers got better, yet their deaths were not as much as during the peak. China was on draconian lockdown from the beginning and for months: tracing, testing, everything you said, and their numbers were bad until all of a sudden....poof.
I think you are seeing this theory all over because people are waking up and realizing the numbers don't match up. Combined with all the suppression of data, lack of testing, etc, logic is rushing in.
The virus is very real, I will agree on that. Its very contagious as experts agree. Is it so far fetched to think that it is in its final phase like other viruses we couldn't come out with a vaccine for soon enough because they magically disappeared?
The "things are bad then ...poof" is seen all over the world and isn't an artifact of numbers not adding up. There's a big lag in time between activities that cause infections, those infections seeding an outbreak of infections, the outbreak of infections translating into clinical cases (which we actually see/have metrics for), and then yet more weeks later a death spike. When the local news (in Texas, Florida, New York, Sweden, etc.) shows people flooding into hospitals, people adjust their behavior and very quickly over a week the infection rate drops. But, there's still a big load of existing infections out there that have to work through the system and things keep getting worse for a bit, but then that bolus works its way through the system and there can be a rapid tailing-off of new cases and deaths. Often the next spike in cases after that translates into relatively few death because the most vulnerable are now taking extra precautions, and often it's a younger/healthier crowd getting sick. Plus, we know how to treat COID-19 fairly well now compared to say March.
People seem fascinated with Sweden so let's look at it:
They started off with nothing more than a light guidance to the public, and both cases and quickly after that deaths began to spike. It's a small country so the numbers are comparable to some COUNTIES in the US, but still... by April they had stronger measures under control including travel restrictions, limiting indoor venue capacities and such, and the population realized that ignoring the pandemic wasn't smart. Cases leveled off but there was still a fair amount of infection to go around; it was too late to really crush the curve. Deaths gradually declined. By June the travel restrictions and so on were eased and people rushed to holiday leading to a big case spike. But the holiday revelers were generally a younger crowd, at-risk people stayed in, vigilance increased throughout the rest of the summer, cases came down, and the death rate decreased to a trickle. Looking good there. But they have to stay vigilant, because all it takes is one sick person to bring it home to grandma.
An important point is that Sweden wasn't really a "poof" in deaths stopping. A lot of things had to come together to get it down to such numbers.
The data come from the individual states; there have been some fails at the state level (in both R and D states). It was a mistake for the data flow to the Feds to have been compromised over the summer by cutting CDC out of the loop; this has since been corrected.
I agree lack of testing is a big problem. We have a testing issue with inconsistent state-to-state situations. A national testing plan was devised that certainly would have been better than what we have now. But it was scrapped. If interested, use whatever search engine you like and look for the stories about the cancellation of the national testing plan Jared Kushner developed. I like
THIS ARTICLE but others may prefer a different viewpoint. In any case, if we had a proper national testing plan and stuck to it, we would be having different conversations now.
To your point about vaccines, vaccines are costly and time consuming. We make vaccines only when there's a business case to do so, and when we can do it in time for the vaccine to be effective. All sorts of companies got all sorts of funding around the world to raise a vaccine against COVID-19, and the good news is the virus is stable enough to likely respond well to the vaccines. Early results are very promising.