The right larynx position in your throat is crucial if you want to sing in a healthy way. When you swallow, you can feel your larynx move upwards. When you yawn, you can feel it lower. When you sing, the neutral position, not high and not low, is the best way to sing. It is the position most people use when speaking. From there the larynx is free to move a little up and down. This movement is a natural thing, it has something to do with the notes and vowels you sing.
High notes ask for a little higher larynx position than low notes. Also, the opera sound asks for a little lower position and baroque for a little higher. Many singers tend to sing with too much tension in the root of the tongue or pull the tongue backwards. By doing that, they disturb the larynx position.
Here is a nice video that illusstrates what happens when the larynx position is neutral, pushed too high and pulled too low. There’s only one classical singer in the video but can still be very helpfull.
Many singers tend to pull or push the larynx.
Singers who pull the larynx down often do that because it sounds better to the singer. The singer doesn’t realise that what he/she hears is not the truth. Read the article What does your voice sound like? The paradox to learn more about this.