absentee ballot voting is legal. During the virus epidemic it was the preferred method and why it was probably higher during a normal election. Even without the virus epidemic it is legal.
Just because your guy lost and you need an excuse does not justify the excuse.
Trump during the last election was all for absentee ballots.
Thus using your logic then Trump had unvetted voting that help him win and he openly pushed his supporters to use absentee voting.
Trump has in the past railed against absentee voting, declaring that "once you have mail-in ballots, you have crooked elections."
www.cbsnews.com
where is your outrage at Trump ?