Reducing the amount of typing decreases the risk of suffering from tendinitis, carpal tunnel syndrome and similar injuries. It helps a lot in managing this health aspect.
Voice messages work well too but cannot be listened to in every environment (e.g. you'd need headphones in an open space office).
If anybody knows about an user-friendly, secure and affordable alternative to audio-controlling your computer, let me know. Siri doesn't go far enough (and lacks in privacy).