Considering how long it has been I don't think we will ever see a Cloud Key Gen 3/3+.
Ubiquiti's Cloud Gateway Max or Fiber seems to be the modern replacement since they do the job of the Cloud Key while also serving as your router and firewall.
In the UK, banks like Starling, Monzo and Revolut (and building societies such as Nationwide) have added a call status feature in their apps [0][1][2] that tells you if they are actually the ones calling.
In the UK all delivery apps [0][1][2] will prompt the driver/rider to ask for ID when the customer purchases age-restricted items like alcohol or cigarettes.
I am not sure why the apps don't get the customer to upload a photo of their ID once rather than get the delivery person to request it for every restricted order?
Ubiquiti's Cloud Gateway Max or Fiber seems to be the modern replacement since they do the job of the Cloud Key while also serving as your router and firewall.