Vloggers are able to have good audio in their videos by using high-quality microphones and not recording in a noisy area. For the best audio quality, avoid noises in the background, which could be done by using some noise-cancellation tools.
It is also good to bring the microphone close to your mouth so that the sound is clear. Quality audio editing will also improve the end result as it would make the voice clear and easy to listen to by viewers.