Parasocial relationships form through repeated one-way exposure. Hours of daily streams produce a genuine sense of familiarity and loyalty, and that feeling gets applied to market calls as though it were evidence of skill.
The effects are specific. Followers copy trades without understanding them, hold through losses out of loyalty, defend the person rather than examining the record, and interpret criticism as an attack on someone they know. That combination is also the ideal audience for a pump.
The corrective is to separate the person from the claim. Judge the method as if it had arrived anonymously, ask what their incentive is, and notice that liking someone is not information about the market.
Related: finfluencer, authority-bias, social-proof, copy-trading-psychology