Wasn’t one of the things Tom (remember him?) said that he wanted people to be able to be at an airport and sign up to Monzo faster than they’d be able to get money from a foreign exchange place? i.e. register and get your card in Apple or Google Pay immediately.
I remember this actually being a thing too, but I’m also well aware that Monzo use the card delivery as a form of address verification. I guess if you’re above a certain risk threshold you don’t get the option?