I’d swear I had a Battle.net account associated with Diablo II and Starcraft in the early 2000s, but either it was deleted due to nearly two decades of inactivity or I used some e-mail address I don’t remember anymore.
But anyway, a 16 character maximum? How am I supposed to work with that? Grmbl.
And then we get these “secret” questions.
So now I theoretically also have to save fake answers in my password manager?
But look, it’s all okay, because there’s SMS Protect!
To sum up, 16 characters is probably sufficiently secure, but why would you ever make that a maximum?