I suggest a forum, discussion group focusing on Starlink Direct to Cell use of Smartphone UT's with the Starlink Constellation.
Done! https://olegkutkov.me/forum/index.php?board=17.0
>> What if one of the satellite networks like Starlink decided to start charging users for data based on their geographical location?
I think that, in the modern world, it is not profitable. Each provider strives to increase the client base and attract people. In competition conditions, everyone will strive to be available everywhere.