If done right nothing will go wrong. It is the "something you have" to go along with "something you know". So "done right" would mean not using finger/face ID as a password, but require typing in a password - at least for really important stuff like transferring money out of your investment account.
For less important stuff like posting on El Reg I'd be fine with a simple ID based on having my phone near me talking to my computer via Bluetooth to give it a challenge/response to login to El Reg without a password on my PC.
What I don't like about this article is saying it will be worth $7 billion to mobile operators by 2024. My carrier has no business being involved in this, and I would never use any service that tried to charge. Though I'd like to see them introduce a service that charges, then see Apple & Google steal their lunch money by building it into iOS/Android using the Secure Element / ARM equivalent of Secure Element on Androids. Any time the mobile carriers get a good comeuppance I'm favor of it!