This is most notable as a problem with captive agents who are effectively insulated from looking beyond the one company that controls them. They note this to be irrespective of the advisers competence and designations. Trusting someone who lies and is unethical is stupid. Find those with the adequate level of competence and THEN select one of those few that you can trust. So when you read these basics, consider the background of most planners- and particularly the fee only planners.
Fees are normally the way to go.