This is what was said but it just doesn’t make sense because of the response I had from Monzo after my complaint;
The purpose of this procedure is both to identify and verify who our customers say they are. In seeing your driving licence, we are informed of who you are, and in seeing your selfie, together with your ID, we are able to verify that you are the person who owns the ID. You asked us the reason why you need to submit these details again when you already did this upon signing up to our service. The reason we ask for this information again, or indeed any form of verification, is because we need to protect certain parts of your account information (eg: PIN, statements) from being incorrectly shared with someone who may not be the account holder but who may have managed to gain access to your Monzo app.
You posed a question in response to this answer, stating that if someone had access to your phone they would already be able to see transaction data, account details and address details. While it is true that if someone who was not yourself were to gain access to your app, they would be aware of your transaction details as well as your account number and sort code and so on, they would not yet have the ability to obtain real, tangible things in the world with these details. Whereas a statement would give them the power to do so. If fraudulent transactions were to take place on your account, we are liable to help you and reimburse you for these promptly, whereas fraud caused by statements could be much lengthier to reverse, so we consider the risk to be greater.
Questions were also raised about the necessity of the identity verification process when you were asking for paper statements to be sent to your home address. Regardless of where we post statements, we are still required to perform identity verification. If someone were fraudulently trying to obtain your statements, there is no reason to say that they might not be someone who lives at the same home address. We are not implying that this is true in your case at all, however for many people, especially those who live in big cities, it is common to live with a few people, some of which they may not be very well acquainted with. So, to best serve our customers, and eliminate all possibility of this, we still need to perform these checks.
I am glad that Statements are going to available on demand without unnecessary checks but just wanted to get some reasoning behind this change. 