(First of all, maybe - e.g. if the advisor is a retired surgeon.)
Secondly, that's not a good analogy; actually making an investment (usually) isn't rocket science and any layperson can do it themselves.
1) It's also fairly common to get a second opinion from a second advisor. 2) If you are willing to do the investing yourself, you won't be charged for that. If you want the advisor to manage your accounts you're paying for that, not the advice. (I disagree with
@aygart, they are selling advice AND products)
Like any salesman, the advisor is going to be making commissions and profits from what they advise you to do. Some will be honest and advise you on what is best for you, some will advise you to buy things that will earn them more, just the same as the car salesman, realtor, sheitel macher, etc.
For instance, I went to
@ExGingi who gave me excellent advice, refused a penny in payment, and didn't sell me a single product. As it happens, I will be in the market for products he sells and you can bet I will be heading to his door. But the fact that he makes commissions or whatever on some of the products he advises people to buy doesn't make that advice bad or dishonest.