Travelling on public transport can be very complicated especially when using more that one mode of transport.
Current ticketing systems require you to either buy the correct tickets before travelling or make sure your travel card is topped up sufficiently. Where there are now contactless payment systems, the experience is better, but these do not cover multiple modes of transport - subway on to E-scooter for example. Commuters do not have much patience for complex commuting systems and are most interested in getting to their destination.