There are thousands of dead people on the voter rolls in every state because there is no mechanism to automatically de-register someone based death, only based on a set number of elections in which they haven’t cast a ballot. There are also thousands of people on the rolls who are also registered elsewhere, because they’ve moved. It’s not an indication of fraud or anything other than a (completely appropriate) lack of link between vital statistics and voter registry databases.
If there were evidence that people were voting after death, then that would be where objections could reasonably be raised. There’s no such evidence, anywhere, because absentee ballots create too strong a paper trail to take that risk, and voting in person at the precinct for a dead person’s last address runs the risk of running into their family, friends or neighbors, in line or working as polling officials. There’s just no sufficiently clandestine way to pull it off.