score:3
Yes, it still happens sometimes - although not necessarily always at the arrival, sometimes even on departure.
For example, leaving Auckland, New Zealand for Argentina, I had my departure ticket from Argentina stored in my email for x months later when I would need it. I showed it to the counter, but they actually sent me up to their (Aerolineas Argentinas) office in the airport to print out my (leaving Argentina!) paper ticket as evidence, before they'd let me check-in for the flight from New Zealand.
Also be aware that you may not have ready access to the internet on arrival - eg in Cuba or Iran. Cuba, I was asked for my travel insurance document which was on my phone, they wouldn't accept it, and had no facilities to print it out, so I was forced to purchase their insurance on the spot. If it was on paper (as another tourist had), it would have been accepted.
It's not necessarily that they're concerned about fraud, sometimes it's just a legacy law - ignore the digital age for the moment and consider the requirement has, in some places, always just been 'you must have written (on paper) evidence of your tickets/paperwork'. If you don't, and it's a requirement for entry, you may well be sent back home at your cost.