No, not at all. I assure you, I have no interest in being a midwife. Doulas are knowledgeable about the pregnant body and how birth works, but they do not provide any clinical or medical care or advice - that is the role of health care professionals like midwives or obstetricians.
At your birth, your midwives are responsible for your medical care and that of your baby. That is their priority, and this should not change. A doula actually supports the role of the midwife by being able to provide the personalised and nuanced support that midwives can't always provide due to the demands of their job.
Your doula can't make decisions for you; a good doula will never say 'I think you should...'. She can only make suggestions for planning and preparing for the birth of your baby, and provide or signpost you to evidence-based information that you can use to make the decisions that feel right for you. Doulas also cannot speak for you, unless that is very clearly outlined in your birth plan. Usually they will empower you to speak for yourself, and try to facilitate good communication between you and your midwife and/or other care-givers to ensure you have all the information you need to make decisions, and to make sure you get the best birth experience possible.