Por que ninguém usou o feitiço de reparo na vassoura de Harry?

Por um lado, não parece que todas as partes dele foram recuperadas:

Slowly, she reached down for a bag at her feet, turned it upside down, and tipped a dozen bits of splintered wood and twig onto the bed, the only remains of Harry's faithful, finally beaten broomstick.
_{Harry Potter and the Prisoner of Azkaban, chapter 9}

A forma como isto é apresentado - isto é, tudo o que resta - implica que não são todas as partes dele. Ele foi destruído para bits , o que significa que seria quase impossível recuperar todas as partes dele. Não faria muito bem apenas juntar metade do cabo de vassoura!

Além disso, a magia tem limites. A vassoura estava realmente destruída. É possível que a mágica não consiga consertar isso.

Por que o Reparo não trabalhou na varinha de Harry? Talvez a estrutura física da vassoura pudesse ter sido restaurada com Reparo, mas suponho que teria perdido a maior parte de seu poder mágico. Hermione tentou consertar a varinha quebrada de Harry nas Relíquias da Morte, mas não funcionou:

‘Where’s my wand, Hermione?’ She was biting her lip, and tears swam in her eyes. ‘Harry ...’ ‘Where’s my wand?’ She reached down beside the bed and held it out to him. The holly and phoenix wand was nearly severed in two. One fragile strand of phoenix feather kept both pieces hanging together. The wood had splintered apart completely. Harry took it into his hands as though it was a living thing that had suffered a terrible injury. He could not think properly: everything was a blur of panic and fear. Then he held out the wand to Hermione. ‘Mend it. Please.’ ‘Harry, I don’t think, when it’s broken like this –’ ‘Please, Hermione, try!’ ‘R – Reparo.’ The dangling half of the wand resealed itself. Harry held it up. ‘Lumos!’ The wand sparked feebly, then went out. Harry pointed it at Hermione. ‘Expelliarmus!’ Hermione’s wand gave a little jerk, but did not leave her hand. The feeble attempt at magic was too much for Harry’s wand, which split into two again

Se apenas ALGUÉM tivesse a varinha Elder ...: |