I don’t know why I thought of this but Sauron ftw-he CAN NOT BE KILLED for he is a Maia (Dark Angel) who’ll exist in spirit if he somehow manages to die. Not to mention the Ring has to be destroyed in Mount Doom.
Voldemort is simply a skilled wizard who happends to spread his soul across various objects that are nothing like the One Ring. Not to mention his wizarding skills wouldn’t last against Sauron’s black magic (DOESN’T EVEN NEED A WAND OR INCANTATIONS!)
Perhaps Saruman vs Voldemort-oh wait, he’d still lose XD