It's puzzling to me how this keeps getting repeated without any strong foundation. This story that others sell your data while Apple holds it secure is a narrative established by Apple that keeps coming up like a mantra.
The implication is that Google is gathering personal data to then then sell it to third parties.
But this is not their business model. They profile their customers via their behaviors and personal data, match them to a persona and then sell services to third parties to advertise to users fitting that persona.
I don't see how Apple is doing any less of customer profiling and persona generating than Google. They are both in the business of profiling their users and then monetizing them by offering services to internal/external customers who look for a certain audience.
The core of this is exactly the same between Apple and Google. Neither of them is selling the user-data directly, they both process it in order to package their users into a service they can sell to others.
The main thing that Apple does differently is, that they took stronger measures to ensure that the data THEY collect from their users can only be collected by THEM.
So Apple took action to protect their unique market position of selling ANY kind of goods to users of Apple products, and they claim that they are more honorable to hold and process all your data for financial gain just because (so far) they failed to compete in the advertising industry.