Have you seen websites in Japan?

Both factors are related, I couldn't find the article I was looking for but this one touches on it too. There's a section for cell phones specifically

https://en.wikipedia.org/wiki/Gal%C3%A1pagos_syndrome

The term "Galápagos syndrome" was originally coined to refer to Japanese 3G mobile phones, which had developed a large number of specialized features that were widely adopted in the Japanese market, but were unsuccessful abroad.[6][7] While the original usage of the term was to describe highly advanced phones that were incompatible outside of Japanese networks, as the mobile phone industry underwent drastic changes globally, the term was used to emphasize the associated anxiety about how the development of Japanese mobile phones and those in the worldwide economy went along different paths.

When a technology advances quickly and gets adopted in the local region (ex. Japan), it can be difficult to change when other parts of the world move forward with a different standard.

The opposite can also happen, where a region is slow to change and then haphazardly moves forward when the benefits are proven elsewhere. American payment systems for example

Their public transportation and a lot of their other infrastructure is advanced, their IT infrastructure is not.

Very surprising indeed. Ever since GSM, i.e. 1992/93, roaming has been a thing.