Carriers usually make it more difficult to unlock the bootloader on their versioned phones. Iirc with some you have to submit a form or something similar to the carrier to be able to unlock it

We need a community for exactly this kind of content a la r/youdontsurf

They’re mostly in rural parts of the states where private (read: investor owned) utilities determined the region wouldn’t turn a large enough profit to expand there and the state’s public utility commission didn’t mandate their expansion