Such technology would make communication with anyone anywhere possible. You could travel in remote parts of Tibet and speak and read with the locals. You will walk into a conference and listen to an interpretation of the speaker given by a machine which never tires or loses interest in the task. You can go to a doctor or hotel or restaurant anywhere and communicate everything you need to, be it verbally or in writing. So, you say, like all dreams, this is impossible.
Language is too subtle and complex for a computer to understand and translate.
Communication relies too heavily on context and intonation, on body language and cultural underpinnings. You might even think that communication between two people is something of a miracle and that language itself is the most dangerous wonder of the brain. As an amateur linguist who speaks some five languages and reads another six or seven, I assure you I understand the difficulties involved in translation or interpretation, be it by a human or machine. Let's keep in mind one basic fact. Most of what people are saying and writing is not high literature destined for Nobel or Pulitzer prizes.