Who needs hard copy, anyway?
Bit difficult boarding an aeroplane showing the booking clerk only your laptop ( if the battery is behaving ) confirmation of possessing an e-ticket - which is something some airlines will only issue now. Theoretically it should work, and indeed some airports have computer terminals for passengers to use to check themselves in with nothing but a boarding reference number to start the process, during which a copy is printed - but I wouldn't want to chance it everywhere !
I realise your remark was tongue in cheek, and I wish I could agree, but sadly Life ain't like that - yet.
A million years ago we ( my crew and I ) were unexpectedly sent home as passengers from New York. No tickets, but advised that they would be issued on arrival at the airport. When we got there 'the girl' regretted that we wouldn't be able to go home as 'the computer' ( a new toy ) was down and she couldn't print our tickets, and no tickets = no boarding.
The Flt. Engineer gave her his pen.