The ability to speak using a microphone is one worth cultivating. Some people do not like to use a microphone when they address crowds. They say they prefer their natural voice. I do not have anything against using a microphone to talk to large crowds. It enables your voice to reach further and so get more people to hear you.
The problem with microphones is often that many people do not know how to use it. As a result, the sound quality may become poor. Hence, they prefer to put it aside and reach out to their audience with their natural voice.
If you want to be a good speaker, especially a good motivational speaker, I advise you to study microphone techniques and master how to use it.