“They are now ignoring the significant majority of asymptomatic people who were being tested prior to January. The numbers are going to naturally drop.”
I think he (2aProtectsTheRest) meant there was no change in US testing, in relation to the number of PCR cycles used (which the WHO recommended dropping, literally on inauguration day). That would also greatly reduce positive test results.
Maybe the little plateau that we have seen in the last few weeks, reflects (perhaps partially) the end of the statistical adjustment to that new sampling method, which you pointed out. Nice to see it turn down again yesterday, perhaps reflecting continued real world decline.
Probably a few factors contributed to the big decline since January 8th (like growing natural immunity from exposure), but some statistical “cooking of the books” really fits the Modus Operandi of the Democrat party. As they say, If they ain’t lying, they ain’t trying. It’s like their main job.
It's the same thing that happened after April 8th and July 22nd: the current wave crested. At the micro level, this indicates that the cohorts mixing over the various holidays (Halloween, Thanksgiving, Christmas, and New Year's) had spread it amongst each other to the extent that mixing allowed. With that spread completed, the number of new available hosts declined and the new case numbers declined as well. As you pointed out, the decline in new cases began well before Biden took office. It began while President Trump was in office. The wave began because households mixed significantly more during the various holidays and the wave ended when cohort mixing declined.
I don't know why people keep expecting some exponential explosion of cases that ends in a sudden magical instant called "herd immunity". That's not how any disease has ever worked in the history of the world. The Spanish flu in 1918 had 4 distinct waves. And it did so without Joe Biden or President Trump. Diseases go in waves. And herd immunity doesn't mean what people think it means either. It means Rt < 1.