They are proposing an app that has your digital ID, that you can show someone to prove who you are.
Imagine you have paid off your mortgage and there are no 3rd party charges on your house. I have intel you are going on a 3 month cruise. I hack your Digital ID. I open a bank account in your name, I take control of all your accounts, pension, bank, etc. II put your house on the market, I use "your" to ID to instruct on the sale, I sell your house. You come home and someone else is living there.
what are you going to do?
The lawyer relied on your ID, the bank relied on your ID, the land register relied on your ID, your pension firm relied on your ID when you asked for a drawdown.