As you note, we need to decide who to trust, and we can't do sufficient research. So we need heuristics.

The heuristics that I recommend are these:

1. Certainty, especially if there is debate among experts, indicates likely cognitive bias.

2. The ability to discuss how multiple perspectives would lead different people to different conclusions, suggests good reasoning.

3. A documented history of quantitative reasoning, along with data showing historical accuracy, is the best evidence of a trustworthy source.

I base those heuristics on the research in https://www.amazon.com/Expert-Political-Judgment-Good-Know/d.... Applying this heuristic to "sounds certain" results in a conclusion, that is an invitation to further research that may or may not happen.