There is another way to look at this.
Hiring others to manage your ads, like any other job that requires deep skills, usually would not give you better results in a short time, but you can still work with them and build.
This time, you're building your freedom by improving their capacity. If you can find a way to build a team that can deliver similar or better results than you, there's your freedom.
As a business person, I suffered this until I decided to work closely with someone long enough, and for the very first time, the person scored well before stakeholders.
She is not even a business person. She just joined me long enough to train a team.