What I like about whatever kind of ticket these are, with a scannable code in the Apple Wallet, is that they don’t get swallowed by ticket barriers. They can also be purchased within a couple of minutes of departure without having to walk to, or queue at a ticket office or TVM (I note Avanti have significantly reduced the number of TVMs available at many former Virgin stations) which may also be closed, however if I am going a long distance to somewhere unfamiliar, where I can’t absolutely guarantee my phone will still be charged, working or even still in my possession when I need it to be, I tend to print out paper tickets. Not doing this for a trip to Ribblehead was certainly a mistake!
Of these, the original magnetic credit card ones are vastly superior to all other formats, whether full A4 or on “bog roll” which as far as I am aware is not machine readable. Other than when I once had to excess up an accidentally purchased single ticket to a return on a train, the only place I have been issued with a ticket on bog roll was Smethwick Galton Bridge and I was charged twice because the ticket failed to print the first time! I have seen people with heavy luggage struggling to unfold printed out A4 tickets to get through ticket barriers without missing their train and also when some of the users of these have purchased completely the wrong ticket which was not valid, but have never had a PDF/A4 ticket myself, except on easyJet.