I get 100/s on an iPhone SE2. 50/s on a Samsung Galaxy A16 which was released in 2024 or 2025, but that is due to an API restriction. You can export from phyphox (.xslx or .cvs). You get timestamps in the first column. Phyphox refers to the raw data rate, not Nyquist freq.

The sensors have analog lowpass filters that can be adjusted in order to avoid aliasing.

In general, with more bandwidth you can do more intrusive things. But if you want to tell wether two people ride in the same car, 50 Hz should be sufficient anyways.

Phyphox has a smartphone sensor database:

https://phyphox.org/sensordb/