The thing is, we had a fully implemented digital arrivals immigration card previously which worked exactly like Singapore, Malaysia, Indonesia etc. You went to a website before hand, filled out a form and received a QR code.
However, the link was poorly communicated. Then when you got on the plane you were asked to fill out a paper form again and then hand both that in and scan the QR code on exit through customs. The government then shelved the multi-million dollar system saying it was too confusing?
I'm not sure how this new system is any better. You now have to download every airlines app you travel on instead of going to a website. Great if you always fly a single airline.
What happens to the people who book cheapest flight of the day and don't have the airlines app? What if you hadn't checked in on the app?