"Science is basically one and the same with critical thinking, a key feature of it is being assailable by itself." Why was the science behind investigating a p

"Science is basically one and the same with critical thinking, a key feature of it is being assailable by itself." Why was the science behind investigating a possible lab-leak hypothesis of the origins of COVID suppressed? Why did the purportedly evidence-based medical community decide that mass public gatherings to protest racism was safe, while closing schools and beaches was not?