The fact that I am a doula makes this statement rather bias, however, I believe that most people need a doula. Let me offer you the following as "food for thought".

Here are some reasons women and couples have wished to have a doula with them. You may recognize a few.

I'd like someone who will be there just for me, independent of the hospital and the doctor, who knows my plans and my concerns.
I need someone to help me cope without any pain medication.
Having someone I trust and have met before with me when I go to the hospital is most important.
I wish to be assured my partner is supported and decrease the pressure on him/her.
I'm looking for someone who understands, and helps me to reach my goal of a vaginal birth after a previous caesarean.
I'd like someone who can help me to labour at home longer (but not too long!).
Someone who can massage away the tension of pain would help.
I would feel reassured being with someone who's done this before and knows what's normal in labour.
I need someone whom I can discuss tests and procedures.
I want someone who respects my decisions for pain medication if I choose it.
I want someone who will be able to explain some of the confusing terminology associated with labour and delivery once at the hospital.
I wish to have someone there who will want to nurture, protect and enhance this very special memory.