What you have to remember is the ticket is never yours and remains property of the railway, if you need proof of purchase then ask for a receipt
Most TVM's will print a worthwhile receipt (all be it very compact)
If you book online then your confirmation should have receipt details
And if all else fails then buy your ticket from a good old booking office (if one still exists near you) as they will give a proper receipt on receipt role
As for the future I do think they need to decide on a technology instead of having several types randomly in place throughout the network: QR codes, print at home tickets, classic mag strip ticket, smart cards, bar codes, long reference numbers, mobile phone tickets......... just pick one and stick with it