Apparently, Peter, you missed my earlier post #9587 showing a couple of ballot fraud convictions in Pennsylvania. I'll repeat them below for your convenience. I don't understand your second complaint. There are many people who have died or moved who should be removed (purged) from the voter rolls where they moved from as they can no longer vote in those election districts. This prevents mail-in ballots from being sent out to people, dead or alive, who should not get them.
You are drawing the wrong conclusions from these convictions. They are examples of ATTEMPTED fraud, not actual fraud, seeing that they were detected and, if it was deemed necessary, the election redone. They show that the system works. And it's a serious non sequitur to argue, as you have, that there must be a lot more fraud going on that we don't know about. To argue that X must exist because there's no evidence of X, well, gimme a break.
We had a major case of attempted fraud here in NC in the 2018 congressional race. An operative working for the GOP candidate was fiddling with absentee ballots and was detected when the elections people noticed that the absentee votes from a particular district were running 61% for the GOP guy while only 19% of voters in that district were registered GOP. So yet again, attempted fraud is caught.
I can agree, however, that mail-in ballots should not be sent automatically to all registered voters. But the process for getting one needs to be clear, simple, and well-publicized.