Many sources are but it is not universal. There are plenty of well developed and executed studies with low risk of bias and minimal to no conflicts of interest.

On the flip side, anecdotal evidece and expert opinion is arguable more biased and less objective.

Lastly, the field matters. Nutrition research is among the most corrupted and biased. It is also challenging to perform trials due to the nature of nutrition and the multitude of variables involved.

I understand where you are coming from, but I think dismissing evidence based medicine - which is a combination of research, expert opinion, and patient values - is an overcorrecttion.