Looking at history is indeed illuminating.
Every single time someone is asked a question of the form "if voting fraud is so prevalent, show me some examples", the most honest answer I hear is "it happened during the time of the Political Machines in certain large cities many decades ago". And when the best and most recent example you can find is 70+ years ago, before anyone having this discussion was even conceived, when politics and tech and discourse looked very different than today, well, that's a loud answer and it's not an answer which says "OMG THE SKY IS FALLING". It's an answer which says "I have exactly zero evidence so I'll pick an ancient example as proof that we must do obviously unethical things right now TO SAVE DEMOCRACY".
It's an answer which says nothing about the issues we are facing, but a lot about your determination to find evidence for your predetermined conclusion, rather than deducing a conclusion from the evidence.