A lot of transit gates do this because you can use Apple Pay or a contactless credit card directly on the gate without going through the intermediate stage of a ticket.
This is very handy in Chicago if you are making a single leg journey. Due to Apple Pay’s privacy architecture it can’t recognize transfers and always charges full fare.
> Due to Apple Pay’s privacy architecture it can’t recognize transfers and always charges full fare.
I don't think this is the case—in London, I'm pretty sure you can pay with Apple Pay and have your fares "capped" (so you never pay more than the price of a full-day ticket). You can also set up an account with your card number (the one on your physical card) and view any recent journeys you've made.
This has nothing to do with Apple's architecture but is probably a limitation of the transit agency's backend systems.
The card number of a given card on a given device does not change between taps for Apple Pay. Otherwise, tapping for refunds would not work, among other things.
This is very handy in Chicago if you are making a single leg journey. Due to Apple Pay’s privacy architecture it can’t recognize transfers and always charges full fare.