I've found that, as the Harry Potter books handle later years in Harry's life the books themselves take on an ever darker, grim and pessimistic tone. This is not necessarily a bad thing, but the problem is that the intended audience also seems to change and grow older along with it, and things that could've been reasonably handwaved away as a 'it's a children's book, no need to look too deeply into it' become things that should be looked into and examined in depth and at length, and these things are often critical parts of the longer term narrative.
Which means that things like the behaviour and treatment of house elves and other non or partially human sapients as well as things like memory and love manipulating magic, which are simple, potentially silly or convenient throwaways for earlier books, take on troubling and terrifying identities when one's attention is drawn to them again. And yet, they are often still treated as a silly or convenient thing to use, often without regard for the consequences towards anyone hit by such magics.
Which means that things like the behaviour and treatment of house elves and other non or partially human sapients as well as things like memory and love manipulating magic, which are simple, potentially silly or convenient throwaways for earlier books, take on troubling and terrifying identities when one's attention is drawn to them again. And yet, they are often still treated as a silly or convenient thing to use, often without regard for the consequences towards anyone hit by such magics.