I suppose it's now become a default assumption every customer is going to own a smart phone that complies with this requirement?

It seems on iOS you'll even need to download an application, which is quite a bit of friction.

In the current economic times, adding minutes onto the user journey is not going to result in increased sales, I suspect the data will prove the opposite.

Using a mobile device is bad enough as it is: TOTP, email, SMS codes, 3DS etc, while you can say this is part of the "flow", it's too much. I can see many abandoned journeys from this.