There are no 100% digital voting systems in the US to my knowledge. Where I live, we have a printout that we can review and then hand over to be stored securely as a paper trail.
There are also multiple checks and balances where they confirm that final votes make sense, and if the counts are off, they count the paper ballots.
To compromise an election, you'd have to take over thousands of machines in multiple states, bypass multiple independent human reviews, and be able to predict where the important counties were going to be. It's impossible.
Notice that nearly every state requires voters to approve the paper copy of their vote.
The digital record is only used to speed up tabulation. In the case of recounts or contested elections, paper records are hand tabulated by humans (a recent example were the Arizona recounts for the 2020 election).
Where are you located that you didn't have a paper receipt you were asked to approve when you voted?
Confidence in the results is only possible thru mutual distrust. Meaning all belligerents recognize and honor the count.
The gold standard for our Australian ballot (private voting, public counting) style system is paper ballots cast at poll sites, tabulated using optical scanners, with results posted publicly the moment the polls close.
With postal ballots, the higher volume jurisdictions use image scanners. Think fax scanners with OCR software to identify the votes. Adjudication is done electronically, by updating the database.
Further, many jurisdictions scan postal ballots as they are received, before election day, running daily summary reports. The fiction is that "final tabulation" is the final report.
For postal ballots, signature verification is being automated. Computers automatically compare ballot's signature with voter's recorded signature. Back when I studied election integrity (20004 thru 2010), the error rate was ~10%, with no independent auditing or verification.
For postal ballots, 1% are lost in transit. What the USPS calls UAA (undelivered as addressed). Meaning a fraction of voters are being silently disenfranchised every election.
That commission has long experience inspecting devices to ensure that they are fair and impervious to unobservable tampering.
Once someone actually manufactures such a machine, then it needs to be used in a system that can detect fraudulent behavior, just like banks do. The system must require an official id, and must ensure voting privacy (sorry - mail-in ballots fail on both of these). It does no good to have a great machine if it will be subject to adulterated or coerced input.
None had a zero error rate. Fully electronic was not preferable because of the lack of audit trail. The best system seemed to be paper with scanners. The error rate was among the lowest and it is fully auditable.
After this study came out I was disappointed that my state chose fully electronic.
But before this last election we went to paper with scanners. The big advantage of course is the ability to recount by hand to your heart’s content. Which of course we did.
For now, paper voting is safer.
I think you've brought this up a couple of times now. Ask yourself, which is likelier:
1) It's a great big conspiracy and everyone hopes nobody sees your posts about this clear backdoor technology, and the mods try their best to delete it every time you post.
-- OR --
2) You're somehow mistaken and it's not all that big of a deal. "