1) Like a car mechanic, these people get paid to sell you solutions and they are incentivized to sell you more.
2) Plenty or honest people have biases because of what they do. If you spend all day thinking about security you might be overly concerned about things that are actually not that risky.
This isn’t to say that there aren’t great people working in the field. But it’s daunting from an outsiders perspective.
Develop an empirical understanding of risk management. While we can't predict the future, through well established techniques and adequate resourcing, professionals can achieve consistent results that are far better than random guessing. Risk management principles drive not just corporate stragegy writ large, but entire industries like banking and insurance.
You don't want your doctor to overlook any problems just because they are rare because your health is really valuable.