1) You could make digital elections secure with issued digital IDs, and simply recording everyone's vote and it would be easily auditable.
But no one wants elections where (the contents of) your vote is recorded somewhere.
So 2) You use your digital ID to be able to vote once, but if you're no longer connected to your vote, it would be much more susceptible to tampering if you can't establish a double blind chain of custody of the votes, which is what expensive in person voting is doing very well.
The first option would be great if you could somehow guarantee a corruption free future of your country where no one will come after you for your vote (hint: you can't).
I’m sure there are other obstacles to surmount, but if that system works, you could have a digital id, use it to vote every time, and audit your own vote without anyone else knowing what you voted.
I don't think we should ever be able to know any individual's vote.
Ballot reconciliation ensures that every ballot printed is tracked, as well as ballots counted and ballots cast match up.
And as it is spread out over counties and districts, any injection anywhere would fail those checks.
I'm not an expert, and there is likely at lot more depth to this, but I did try to read up on it after the 2020 election and was sufficiently convinced at the time at least, but I'm happy for anyone to correct me.