It enables Android’s umbrella corporation to track the location of the device with sub-mm acuracy at 60Hz just for their crowd-sourced research purposes. And the benefits to the user are that it tracks a couple of extra satellites, fills up your storage space rapidly, eats all your data bandwidth, and increases your personal ranking in several corporate databases.
( actually I’m just kidding - I have no idea what it does )
Google, for example, will not allow voice searching (“Okay Google”) on Pixel phones unless you give them permission to track and log all your interactions with the world. Good thing I can still type! I don’t know if this is on all android devices or just their brand. Don’t worry though, it’s only meta data.
AFAIK, Android applies duty cycling to reduce power consumption so GNSS signals are not tracked continuously and moving on from I think since Android 8, that has become an option in developer settings. So the API allows access to raw measurements (pseudorange, doppler, etc. depending on your phone model). Seems like more and more phones have coming out with improved gnss and dual-band capabilities of late (L1/L5, etc.).