"Leading the world"?
Somewhere behind, oh, Japan, and the Netherlands, I think also Sweden, and probably a few more places. Japan isn't a particularly good example to follow because their social structure allows one to do things that wouldn't work just about everywhere else.
In the low countries they've forced "contactless" through nationwide as the sole system in a way that pissed people off no end. Just about every aspect is set up such that the customer always gets shafted this way or that way. Possibly something to do with the top brass having been shown to be outright corrupt. But wondering just how those rfid vendors got footholds in various appliactions without benefits obviously justifying the costs for the end user would be digressing.
The reason cited for pushing through regardless with a shown to be broken and barely functional system was fare dodging, which got halved. A nice boon in Amsterdam and Rotterdam where the percentages went from just shy of ten to about five percent, in tram and metro lines. Everywhere else it already was about one percent, scarcely justifying the cost of the system which is somewhere north of three milliard euros and counting, though nobody dares deign a tally.
Also something people don't like admitting is that bus loads across entire provinces dropped by a fifth. Might have something to do with the cost of entry as well as the cost of use for the casual user. And that's without considering the risk of having your card blocked at the drop of a hat for suspected fraud which usually turns out to be a glitch in one of their many dodgy systems, but takes ages to rectify; yes that happens quite a lot. There were plenty of promises, such as that costs wouldn't rise, but with a system that expensive, well, each turned into just another broken promise. What else is new?
Instead of being a truly better, more useful system, "contactless" for public transport in NL has given rise to more and more different, regional kinds of one-shot cards to try and win people back despite this horribly expensive abomination of a project.
I could give any number of further examples, but suffice to say TfL would do well to take a close look indeed at Trans Link Systems at all levels, as an object lesson, what am I saying, a multitude of object lessons, of how not to do it.
Nota bene that above doesn't even begin to deal with privacy issues, which were entirely too hard for TLS so they bodged and dodged and fudged and ignored them, but that also need solving for a more general use than oyster is today.