We are not doing 16,000 / 42 = 380x more tests per day on March 20th vs March 1st. It’s not even obvious if we are overlooking a larger fraction of infections today than back then.
Also of note that 30% daily increase I spoke of underestimates the difference between March 1 and March 20th.
New infections are modeled to noticeably slow down once ~1/5 of the total population is infected, but at that point things have already fallen apart.