I think it depends what they do with it - it’s just that in its current form it’s largely pointless.
I did hope they might try to extend the contact standards so you could include sort code and account number in your mobile / Google / Apple address books so they could be reused across bank accounts or devices, but it looks like that won’t be happening:
Instead, the half-finished(?) contacts rework seemed to suggest you could have a contact within Monzo that you could hook different accounts off of (you can kinda do that at the moment, but it’s still a pain):
It just feels messy and unfinished, imo. I’m just not sure why a button to open your contacts is useful - if you can’t put your bank details in there?