Yes, as with Octopus in Hong Kong which is generally regarded as the pioneer citywide "stored value" card. Actually the real pioneer was BART in San Francisco in 1970, but that was just on one system, not citywide.

The London one suffers from premature implementation however before all the issues were ironed out. It's not clever enough to recognise that if you make a few journeys in a day that charging the travelcard fare is the correct one, and it will instead go on racking up the expenditure, which means it is not appropriate for high usage travel. And it doesn't work well with either National Rail trains or traditional Routemaster buses with conductors.