How about vote by email? Go to a vote.gov, fill out your ballot, it gives your a PDF you can review, you email that to your board of elections, they reply with a "got it!", and they're counted like all other mail-in ballots on election night.

Same process, just s/USPS/SMTP/. But if that's fine, why make the user jump through the email hoop? Hell, digital ballots would give you stronger guarantees for verifying your vote. Publish all the ballots publicly and base the final tally for digital votes on that public ledger. Every voter will have a code they can use to pull up their specific ballot and see that it's correct. And since the codes are public that's not actually enough to prove it was yours (yay non-repudiation).

No cryptography, no hashes, no zero trust proofs. The internet is only used to move a document from A->B and security model could be explained to the least technical person since it's a direct analogue of how you would do it IRL.