Not necessarily. Planar magnetic headphones have an excellent reputation in the audiophile community because some of the most popular models feature those drivers. They tend to offer exceptional detail for the price and, when tuned correctly, can deliver powerful bass and excellent soundstage. But, the same can be said of dynamic drivers. It really comes down to the individual headphone you’re considering. Before pulling the trigger, be sure to read professional reviews from reputable sites like Popular Science, Headphonia, and Headphonesty. Also, take into account the impressions of real users on forums like Head-Fi and the r/headphones subreddit. While dynamic drivers are often cheaper (not always, see the Focal Utopia), there are many amazing pairs of headphones that use them.