Apart from the fact that I still believe that the only one who is permitted to save passwords using any kind of reversible encryption ever is my password manger, the other problem with that is that you still need to share your password with someone. I have a fundamental problem with that. A password is used to authenticate for a given account, and for nothing else. Never share a password with someone else. It’s just that simple. (Although, even I make one exception to that rule for my wife, but there we go.) Also, never ask your users to share their password for x with them. It’s that simple. And I really think it is very irresponsible of any organisation to ask users to share their passwords. That is training them to fall for phishing.
Any org that asks users for their password gets immediately downgraded on my internal scale of trust. That includes Apple.
Incidentally, as I have outline elsewhere, Monzo doesn’t come across as being too good in security to me (2nd-last para), so that gives additional cause for concern.