I blame the IRS, not the taxpayers, here.  Why they couldn't have issued a standard tax form in early 2021 (you know, the same time you are getting all your other tax forms) reporting the total stimulus amount paid out in 2020 instead of sending the lame letter that was issued at the time of the stimulus payments and easily mistaken for junk mail is beyond me.

Relying on clients, especially those with less than perfectly organized lives, to self report their payments was always a disaster in the making.