That's true, but again, every professional is in the business of making money. I don't do brain surgery on myself nor do I paint my own cars. I don't have the knowledge or tools.Fiduciary or not, every financial advisor's job is to make money off of you. This is done by reducing your profit.
It is common to see a 1.5% charge. On a 6% year, that's 25% of your profit. Which never gets to compound and earn.
Just a couple of the buildings your money builds:
I believe you can be self directed to a point and that point varies for each of us.