Theres a few reasons. My first and main reason is the fans. People who read harry potter don’t seem to read any other non fiction. I realized that this was true of me as well. I feel like it prevented me from finding multiple more interesting stories than just one series
two, the fans dont seem to have the ability to process real world events outside parables and relations to the books. This is like, doubly dangerous since its a childrens book. In real life, good and evil are subjective and have blurred lines. This is explicitly not the case in most commodified fantasy. The bad guys always associate themselves with evil symbolism, or unkindness. Voldemort had lots of snake imagery, and was shown killing the innocent a few times. Snape was rude to Harry in his introduction to set that as his tone. It removes the moral dilemma as a burden from the reader. Good and evil are clearly defined and unambiguous and no critical thinking has to occur. In reality, decisions can be good or bad, things are complicated. In this cheap fiction, anything Harry does is automatically morally good, and anything the antagonist does is morally bad because hes big and scary and ugly and gross. Lifts a big weight off the shoulders of the reader. Maybe you could argue that all fantasy is supposed to be escapism and these burdens shouldn’t be in fantasy for that reason. Then I say fantasy should remain fantasy, and not be used as a moral framework for reality.
third, as a child the writing was fine, but as an adult, its kind of bad. The strongest wizard is a high school principal? Why is this terrorist cell obsessed with a middle school boy? Everyone gets assigned into one of four groups and one group is just straight up nazi kids? Snape was a weirdo how are you gonna bully your dead crushes son like grow up and take a shower bro. How did Hermione get laughed off for protesting against slavery? She went to the dance with a professional sports player? Less and less things make sense. And not even in like a “wizards could still use guns” kind of way.
Thinking about the last time I read Harry Potter makes me think of like, a british mcdonalds. Theres nothing, no moral. The world, both real and fictional is full of conflict, suffering, injustice, slavery, and poverty. Its totally ignored. Harry grows up to play wizard cop and maintain a status quo which holds him as a celebrity. I am losing sleep again over another climate headline.
Adults who still read Harry Potter enjoy being infantilized. Its like a sedative for a dangerous and scary world. Its easy to become numb and tune out reality, live in a world inside your head which might be more rose colored and you have some semblance of control. Unfortunately, doing this, to me, feels like giving up. There is too much passion and beauty worth fighting for. Little by little, we will carry on.