I’m inclined toward the argument that we are all biased to varying degrees. An “expert” is going to be biased toward their subject of interest. In many cases, you want someone who loves their subject matter to be your source. For example: Soccer is my favorite team sport, so it might be a good idea to ask me about the rules of the game.
On trickier subjects, I want the bias to be presented up front, “As a Christian…” “From a Jungian perspective…,” “As a former…”
Bias recognition and proper appropriation are my major markers for whether a source is trustworthy or not.