Except that here in the US a non-trivial number of politicians of a particular persuasion[1] actually believe that government issued ID, of any kind, is the "mark of the beast". There's a reason that Real ID had a lot of push back. Having USPS, already a political bogey-man for that same crowd, become a holder of "identity" is probably going to face a lot of pushback.

[1] just one, recent example... https://www.al.com/news/2022/10/alabama-gop-chairman-made-th...