Are you advocating the idea that this is more difficult, or less likely, than hacking electronic ballots? Where is the evidence for this?
Having come from a major Democratic city political machine, I can assure you — it’s much easier for a party operative to pay someone a bonus to simply throw away ballots cast for a challenger than it is for some mysterious Russian with no idea who the votes are even for to change the results in an electronic voting machine over the internet.
It’s like you’re claiming on the one hand that fraud doesn’t exist, but if it, like, did, don’t worry about the easiest method of doing it — let’s prevent the most complicated! It makes no sense.