Apologies for not responding sooner with specifics to @bigfatsurprise@ProfTimNoakes with specifics.
Here are some......
Yes, RCT’s are design w/ highest causal inference
But many topics can’t be studied w/ RCT
Can’t randomly assign & follow until morbidity/mortality:
*Cigarettes & lung cancer
*Parachutes when sky diving
Lack of RCT does not = lack of evidence