I would take the analogy even further. While you may physically have the capability to do as you please with the house you own, you do not have the legal permission to do so. The exterior is heavily regulated by city landscaping regulations. The interior structure is heavily regulated by building codes. Mess with wiring and you can say goodbye to your electricity grid connection. Mess with pipes and no insurance will cover you.

Similarly, I own a car. Can I take off the seat belts? Physically, yes. But legally, a vehicle without a seat belts is no longer a car and I lose the right to enjoy driving it on public roads.

Ownership was never about physical possession. It's about gaining some rights.

Back to phones, the challenge is to demarcate what rights does an owner get when they buy a phone. To side with Epic Games, the discussion is even more complicated by Apple's (purposeful) confusion of owning a phone with having access to an ecosystem of apps for that phone. I can do whatever I am capable of with my iPhone, but I may lose access to the ecosystem of apps.