It doesn't have to be one or the other - for repeat simple journeys, a machine is OK, but the GB rail system is so Byzantine that anything 'unusual' requires real effort and inside knowledge.
It's a few years ago now, but my first Stafford/ferry/middle of Ireland ticket actually took three days to achieve, including me getting a ferry brochure from a travel agent, to persuade them it was possible.
I've had a hand-written ticket, because the computer had no ferry times installed, so the journey was 'impossible', resulting in it refusing to print them.
I tried to do it on the phone, only to be told "We don't sell through tickets to Ireland" - "But, I've got the one in my hand from three months ago, I've been using them for years. I did the last one over the phone" - "You can't have. We've never sold those tickets" - "OK. Can you put me onto someone else who might be able to do it?" - "No, if I can't do it, nobody can!".
Whatever it is, it needs to work - and to work for the passenger.