And how many of those 6400 ballots in Michigan were timely mailed in order to ensure delivery on or before Election Day? We can (and should) make mail-in balloting available to everyone, but we can’t make them drop them in the mail on time.
You may direct your complaint to the State Bar of Texas.
Both of the stories you cite (and it’s the same story in two different outlets) involve blank ballots that were not delivered to the voters who requested them, not filled-out ballots cast by mail. All of those voters were obviously aware that they didn’t receive the requested ballots and had weeks to get the error fixed. And 175 ballots out of 1.28 million absentee ballots requested adds up to an error rate of 0.01%, meaning that you’re about 170 times more likely to have your Wisconsin mail-in ballot rejected for not filling it out correctly than to have it fail to be delivered to you.
To be clear, I’m not denying that some tiny number of mail-in ballots that were mailed on time will end up getting delivered too late to be counted. The only world in which that fact matters is in an election so close that it might equally have been determined by a butterfly flapping its wings in the Amazon.