I only watched three Harry Potter films. The first one, the second one and the fourth one. After that, I dropped the series back in 2005.
With every movie, there are new characters, new weird names you have to memorize, new magical spells with weird names you have to memorize, cloudy stakes (even though the main threats were Boldemort, some of the Malfoy members and the goth teacher) and, speaking of it, I think it’s a law of nature that any franchise with so many movies ends up either flanderizing someone or retcon something.
And considering that some reviews I’ve read about those CGI prequels were harsh on the films, I think I did good on dropping Harry Potter. I no longer have interest in magic after all.