If you're not comfortable with how your voice sounds, find yourself fatiguing you throat too easily, or even just want to be heard better, then speaking voice modification could definitely help you. With simple exercises and routine practice, you can make yourself sound more genuinely "you."
If you're struggling with being understood.
Everyone has an accent. Unfortunately, not everyone understands every accent. For actors, getting the audience to understand them is one of their most important jobs - so learning the features of a non-regional English language accent can bridge many gaps in your performances and open up professional possibilities. Even outside of performance, it can also be useful in communicating on a daily basis - especially with strangers and business associates whom you may only be meeting once.