Yes. Adults enjoy them. They are well told tales. The interest in the stories also creates easy access points for conversation; a la how’s the weather or what is your favorite baseball team up to?
As for kids, having taught middle school teens, and having found them as tough as any crowd, the Potter series was a nice point discussion. There is symbolism in the books and I often used identification of the symbols in the books to assist youngsters in identifying symbols while discussing the Gospels.
Some of my students found correlaries in the books that they felt related to faith and the Christian faith of the author; Harry is a character who is often challenged by that which is obviously evil, he struggles, is sometimes beguiled or confused by evil, but in the end chooses good.
As with anything, all things in moderation. If your kid is strictly reading books of the wizardry genre or seems to have an attraction for the occult one should be cautious. My 8 year old has no trouble understnding that this is fiction.
In some ways, the scariness of the creatures that the kids conjure up when they’re not playing by the rules is a discouragement from messing around with the occult.