What is a fake registered voter? When you register to vote your name is tied to your number and if someone else tries to register with your number the duplicate number immediately says "no can do, the number has already been used". If you try and register with a fake number that number immediately says "no can do, no such number". Only one person can register with one SSN. If someone makes 10,000 fraudulent mail in ballots when they verify the names with their numbers they will have countless ballots with either fake SSN numbers or numbers that have already been used, they will be caught.
It is not possible for someone to vote twice without it being caught. It is not possible for a bunch of fraudulent mail in ballots to be manufactured without it being caught. Every precinct knows how many voters are registered in that precinct and if the total number of votes exceeds the number in the precinct it will obviously be caught. Anyone who actually thinks it would be easy to commit voter fraud and have thousands of extra votes counted is a fucking imbecile, it can't happen.
Verifying signatures would be impossible, we would still be working on the millions of 2020 signature verifications, my own signature would not match mine from 10 years ago. What is to prevent me from signing 100 ballots? What is to prevent me from showing a picture ID 100 times? Every registered voter is in a database with their valid SSN. Every registered voter can vote once and only once or it will be caught.
The only logical way to have fraud would be for someone to rob the post office and steal 100's or thousands of ballots before they were sent out, vote on them and then sign the name thats on the envelope and mail it in. Except when 100's or thousands of people come forward saying where the fuck is my ballot, it will be caught.
It truly is amazing that so many people are stupid enough to believe that asshole and think thousands or millions of fraudulent votes could be cast without it being caught.