Because the old ancient wizard has reason to believe souls exist, which means that while it’s probably possible to keep Hermione’s body functioning, there’s “a burst of something… too vast to be understood” that’s just gone missing.
Mind, that doesn’t stop someone from figuring out a way anyway. Harry certainly plans to. It just makes things significantly more difficult.
Old people, & people immersed in the traditional wisdom of old cultures, believe many things that have playtested as useful beliefs over a very long period. It doesn’t follow from this that no dross creeps in.
Because the old ancient wizard has reason to believe souls exist, which means that while it’s probably possible to keep Hermione’s body functioning, there’s “a burst of something… too vast to be understood” that’s just gone missing.
Mind, that doesn’t stop someone from figuring out a way anyway. Harry certainly plans to. It just makes things significantly more difficult.
Old people, & people immersed in the traditional wisdom of old cultures, believe many things that have playtested as useful beliefs over a very long period. It doesn’t follow from this that no dross creeps in.