The point this story is trying to make is that the machines themselves are unnecessary - just tap in with your normal contactless credit card, debit card, oyster, or phone to get the best fare.
I disagree the machines are not needed. Often when it comes to the railway people argue for things that conveniently ignore edge cases and pretend public transport isn't for all the public. Our railway system is incredibly complicated.
Ticket desks worked/better in bright light, if you're blind, deaf, unfamiliar with the machines, wanted to pay in cash etc etc