Your parents might bring up the point that having a phone would lead you to being on it too much and disconnect you from the social world. To argue this, you could say that they could set a screen time on your phone that allows you to be on it for a limited amount of time. Another argument your parents could bring up is that it's very easy to be exposed to negative content, such as bullying, violent images or videos, etc. You can counter this by saying that they could monitor what you are looking at on your phone. Lastly, your parents could say that the phone could be a distraction to you during class or other important times. This could be fixed by simply putting the phone on silent, or leaving it at home all together.