While you can do this without AI, AI can potentially offer some benefit. Primarily, it can learn to understand the context of what's being discussed and translate meaning more so than just words.

Translating words for words is one thing, but when a certain phrase has an unconventional meaning in one language when used in a specific context, and you translate the words to a different language, that meaning can be lost. Being able to use AI to understand those nuances, and hold context on an ongoing conversation, can potentially make the real-time translation much more meaningful (by translating the underlying message, not just the words).