When you break up old formal constraints and allow more degrees of freedom, it's terrifying.

Now you have a whole new question you never had to ask yourself before: "which way is up?"

The answer to that question is now relative!

Different parties will have different answers.

When you go weightless for the first time in space, a whole new dimension that didn't used to change becomes relevant.

More degrees of freedom (great!) but now even harder to coordinate and find your bearings.

Having solid ground that users can come back to helps them get and keep their bearings in a new system.

The home screen is a home base on an iPhone.

No matter how lost you get, you can always get back there.