The midwives/doulas are valued for their emotional support and expertise plus can advocate for you. It's still important to have access to a doctor in case it's needed, but basically all my friends have had doulas and found them to be incredibly helpful for the process (they get involved early). I don't think this is an either/or--it should be a both/and.
I don't really get why you would need somebody to "advocate" for you. Doctors are already bound by their professional oaths to have your best interest at heart. It's totally unclear to me why you'd want another less-educated and less-informed layer between you and the doctor.
My son was born in hospital with OB attending. It was a totally normal (I.e. With epidural, vaginal) birth.
I would have said the same thing, until I gave birth. One of my main things was that I did not want an epidural. I have a serious needle phobia, and them sticking a needle in my back was not going to happen. And yet at one point, the MD who had agreed with me during my nine months of pregnancy says let's get the epi prepped. I flipped (especially since I was in middle of labor) and was screaming no epi, no epi. Yet, they did not listen to me, until my husband spoke up and said she is serious, no epidural. It has been shown that women are not as listen to as men, and especially not listened to during birth.
It also has been shown that having a support person (husband, doula, what have you) does decrease adverse outcomes for both mother and baby. That is why, unlike most other medical procedures, you can have a support person there. If you don't think your SO will get your needs across, you may need to pay someone to do so. That said, this happens in other medical fields and having an advocate is starting to become more popular.