I think an NDA can facilitate the road to obtaining a patent. An NDA can help protect the idea from getting into the wrong hands, and legally allows you to discuss information without worrying about leaking it. You would have all parties present sign an NDA before a patent is even issued.
A patent protects intellectual property for a set amount of time. So if you don’t need to discuss pertinent information with others you can apply for a patent without ever creating an NDA.