Like it or not, clearly, we are now well into the digital age, and it not if, but when, physical ID such as passports, driving licences etc, will be replaced by digital ones, on your phone, on whatever device you may be using, Passport control, could just as easily become face scanners, and a reader you would download vises etc onto your phone, just scan in, when you book your flight, and when you enter the passport control area, this for the bulk of people would certainly speed things up, and customs staff would only need to get involved when someone's id flags up an error
Things like driving licences, etc, again, how many of us carry our phones on us, 99 per cent? we already have such things as digital tickets, railcards etc,