Apple Map - Outside of US, Apple Map is literally useless in Asia. It is very good in China because all mapping Data belongs to Government. It was OK last time I used it in UK, but failed in many other parts of Europe.

Apple Music - It took them years to add basic thing like lyrics. Songs Selection were far inferior to Spotify on International Level. Songs are missing on a yearly License renewal basis. And when they were added back, they have a different ID so your previous play list don't include them anymore.

Apple Pay - Pay Cash only in US. Many of the Points and Rewards System aren't even available when using it. They are finally figuring out Transit, but it is slow process.

Apple News - Outside US?

iMessages - I know many are happy with it. But the system constantly have issues with Groups where some people don't receive message. Comparatively Line, KakaoTalk, WhatsApp, Telegram, Signal, etc... None of them had any problems.