Thats more a network limitation, the networks have to buy in the kit to do it and they dont bother. I think only o2 and possibly EE do it in the UK.

Another iOS thing the rest of the world is still missing is Voicemail Transcription.

Been out for nearly 3 years, yet remains USA-only to this day.

I'm on Three in the UK and no visual voicemail, but subscribe instead fo HulloMail which does voicemail transcription and is a very low monthly/yearly cost.

Would still rather my network provided it though, but it's been 10 years now and Three still haven't updated their systems, so I doubt they ever will.