The intentional slowdown was directly related to battery life. They got sued over it. But if you put in a new battery, performance returns to previous levels.
Apple even tells you in your battery info settings page whether you are running with "Peak Performance Capability".
So generally I believe that Apple respects privacy more than google overall.
That doesn’t mean Apple is some privacy beacon.
But I have never had Apple randomly turn a setting on my phone on. Google got caught redhanded doing that. I had been using android for years until that incident.
Apple I buy my phone. Google I am the product.
If he is interested in game development, I recommend buying a couple Udemy courses on Unreal Engine development.
You will need to make sure your MacBook is powerful enough to run the unreal engine development IDE.
But if it is, he will be able. To quickly put something things together and see the results.
My son(9 years old at the time) put together a small game over a summer via a udemy course and unreal engine.