YES! YES! And more YES! If you think about a wedding even 50 years ago they were much, much more simple. Now most weddings are complex events that require thought, planning, and frankly a lot of time. I would spend hours upon hours as a wedding planner on each individual wedding.
Wedding planners are vital. Pick someone who works in the area where you are going to get married regularly. Someone who you feel comfortable communicating with and who has experience.
Wedding planners can help you navigate through the long list of tasks, help prioritize and help you to really think through all aspects of the day. They are an unbiased neutral party who can help with family dynamics and really listen to what you need.
They have vendor relationships and can help you narrow down from endless lists and options of wedding vendors. They have industry experience and can help structure the day properly so that your timeline and plans are realistic which can save so much stress. Planning out the day properly is crucial to it flowing smoothly and not feeling extremely hectic (well it will still feel somewhat hectic, but a timeline will help!).
The week/day of the wedding you are the person everyone wants guests, vendors, and family. They will all be knocking down your door and to have someone available to answer questions and help with logistics is invaluable. I really can't say enough about what an asset a wedding planner is at a wedding!!