[withinboredom]

> which is used as the second factor (you get a push notification, you have to unlock and accept the transaction).

This breaks more often than you'd think. I'm still locked out of Facebook on one device because I can't seem to receive the unlock notification and I'm terrified to reinstall Facebook on my phone and then be actually locked out. I'm not a fan of Facebook, but it's the only way to contact some of my friends/family these days via video.

I've also had similar issues with actual banks where the notification appeared and I accidentally tapped "decline" or even dismissed the notification by accident. I've also never received them (mostly with ~Transfer~Wise). Edit to add: I've also been too lazy to walk to the phone charger to press "accept" and just given up.

I think it's a pretty well known phenomenon in ecommerce that the more "clicks" you add to checkout, the less % of people that will make it to the end. I don't see this decreasing cart abandonment at all.

[judge2020]

Google, Duo, and Authy all seem to do fine even in low-data (1 bar non-lte 4g) scenarios, so that's probably a bank & facebook issue. They probably rely on the push notification to carry and push state to the user's device with no backup mechanism for when this fails.

[withinboredom]

Of those three, I've never had an issue -- and I pretty regularly wander around with 1 bar non-lte quality service.