You want to call my mom and read her an 18 char password? I'll give you her number, let me know how it goes! So I think it should be obvious when I say my mom,

You want to call my mom and read her an 18 char password? I'll give you her number, let me know how it goes! So I think it should be obvious when I say my mom, that's a user I have no control over, I can't yell at, I want to make sure there are no mistakes, and that she can't mess anything up on her end like writing it on a sticky note... If you haven't figured out, mom is the worst possible case for a user. You're getting lost in the details. It should be SIMPLE to securely share credentials or codes or details with someone, and that can't be done if a piece of paper is your system.