There are good reasons to have your supervisor present at your viva.
They can make notes on your behalf. After the viva these notes could be helpful for completing corrections or continuing research. Your supervisor could also be a friendly face in your viva. It’s not supposed to be terrible, but knowing they are there could help how you feel.
There are also good reasons not to have your supervisor at your viva.
They can only be present: they can’t ask questions or respond to them. And it could be that while they are a friendly face that might not be what you need. For how you feel about your viva, an audience of any kind might be the last thing you want.
Rather than weigh pros and cons, reflect on what you want and what you need for your viva. That might include your supervisor or it might not. Whatever you decide your reasons are good enough.