The problem with dead people on the voter rolls is that if that fact is known by vote-cheaters a living person can illegally vote as if they are that dead person, and particularly using the many extra ways voting has become possible outside actually appearing at the local polling station.
The problem with fixing the issue is that little is in place in law or practice for getting death events notified to, or searched by, those responsible for voter registration.
The fact is that voter registration has been the poorest step-child of publicly financing & priority of government operations.
Interesting that voter registration upkeep is such a poorly maintained area nationwide, no? That something so primary, so vital to honest representation is allowed to languish. Almost as if by design...