I believe the issue is that absentee ballots have required PII that is not normally available to your average scammer. Yes, a family member could use your personal information to request an absentee ballot and sign both the witness block, as well as forge the signature of the person in question, but this is far more difficult than just filling in an unrequested mass mailed ballot with any old information. This was the big fight about ballots being adjudicated, even though they were unsigned or the signature didn't match the registration signatures or the ballots were incompletely filled out like forgeries. It doesn't seem like a big difference, but it actually does make a difference. The rules for absentee ballots is more difficult to cheat because there would only be a limited number of ballots that be fraudulent. Ot would take a huge amount of coordination and it would be far easier to detect.