Voldemort isn’t clever enough to just kill him by non-magical means.
Well, you know how it would actually play out, given Canon!Voldemort
“Okay, my wand didn’t work against Harry, and a borrowed wand didn’t work against Harry. What I need to do is get the ultimate wand!”
“Master, it may be impertinent of me, but why don’t we just get you an AK-47 and let you shoot him? Or maybe a grenade launcher or something?”
“But then I won’t have defeated him with magic! My magic must be the mightiest!”
“Um, wait, if you need the boost of the ultimate wand, isn’t that already proof your magic on its own—”
“Avada kedavra! All right, anyone else have helpful suggestions?”
Well, you know how it would actually play out, given Canon!Voldemort
“Okay, my wand didn’t work against Harry, and a borrowed wand didn’t work against Harry. What I need to do is get the ultimate wand!”
“Master, it may be impertinent of me, but why don’t we just get you an AK-47 and let you shoot him? Or maybe a grenade launcher or something?”
“But then I won’t have defeated him with magic! My magic must be the mightiest!”
“Um, wait, if you need the boost of the ultimate wand, isn’t that already proof your magic on its own—”
“Avada kedavra! All right, anyone else have helpful suggestions?”