While reading this I got a sense that all of these anachronistic processes would not exist if voting would be moved online. So many of the contentious issues we see here (mail-in ballots arriving late, machines not printing receipts, etc..) would simply not exist. Online voting seems like such a simpler approach.
1. Your physical signature witnessed by a poll worker, and your identity and presence physically recorded in several different locations.
2. A physical paper ballot only accessible by poll workers.
3. A locally stored electronic ballot only accessible by poll workers.
4. Multiple physical receipts with your votes, distributed to many different physical locations only accessible to poll workers.
5. A trained poll worker available to help at the time and place that you vote.
6. An easy backup plan if something goes wrong.
Online voting is optimized for the happy path, but handling all the edge cases where something could go wrong is extremely difficult to implement and difficult for voters to understand. With online voting you need to ensure the security of the voter's physical device, operating system, web browser, each link in their internet connection, and all of those for the voting servers as well. After implementing processes to secure all of that, you need to communicate the security in a way that an average voter can understand it. You also need to think about what to do when a voter needs help, or their computer crashes mid-vote, or their power goes out, or someone sends them the wrong link, etc. etc. etc.
Current processes are a little more complicated up front, but processes for preventing and correcting errors are easy to implement and understand.