You're totally entitled to prefer stories and worlds that are grounded in realism - others enjoy reading stories that are flying high in fantasy far from the places we could ever hope to explore in our universe or anything that follows its rules. Absolutely not a defense of harry potter for what its worth, fuck jkr and everything she makes. But there's such a wealth of stories to be told that don't follow our rules, and many magic systems do follow hard and fast rules, they just don't happen to be the ones we follow in our world.