A sponsor was hugely important to me. Only slightly less important now, but vital for that first time through the Steps.
The surrender aspect mentioned here is real. That's reason enough.
I think there is huge benefit to being shown the directions out of the Big Book by someone who reads it with spiritual eyes. Meaning someone who has been through the process. It's a very different take than what I can read with my delusional alcoholic eyes.
If you are around long enough, you will see hundreds of people who are 'doing great, going to 4 meetings a week' go out and get drunk. And stay drunk. Some make it back after getting beat up for a year or two, and some do not make it back. It's just the facts.