I had it installed since yesterday but like I said downgrading the iOS deployment from 17 to 16.4 fixed the issue Xcode is taking just 0,3 from my CPU now based on what Activity Monitor shows. I have tried to get it back to iOS 17 and the CPU goes over 100%

this solution is not good. Stop copy pasting crap around the internet

Firebase supports Sign in with Apple as well. Now the thing is , if your app is going to scale and you want to support Android as well then you should consider Firebase. CloudKit doesn't support Android and the docs are very poor on how to implement in modern apps. Just go for Firebase