The U.S. Department of Commerce requires that all exportable GPS products contain performance limitations so that they cannot be used in a manner that could threaten the security of the United States. The following limitations are implemented on the Trimble…
What does the actual real time computation? The phone or the GPS chipset?
The local hardware is limited (That’s the export control).
But I believe the consumer-accessible signal from satellites is also limited on accuracy.
https://www.gps.gov/systems/gps/performance/accuracy/
Bottom two sections are most relevant