Who should do XCode UI testing

I am not sure this question belong here, This is a software project management question.

Don't down vote, Let us sort out in peace if I need to post it somewhere else.

I was recently trying to include XCode UI test in our iOS project. We have a testing team who does and run automated UI testing every night, they user Appium.

Since I feel XCode UI Tests is better than Appium.

Should We Developers do all the UI tests in XCode and is it the job of the the QA guys to do it?

Should XCode UI Tests better than Appium Tests?

Should both Xcode UI Tests and Appium Tests be done?