The overwhelming majority of consumers just prefer larger screens (myself included). People seem to forget that Apple releasing the Mini was them listening to the minority and the sales numbers if it were poor versus the rest of the lineup.
I find reading ebooks and long texts like wikipedia a lot more enjoyable on my 6.8" AMOLED panel than on the smaller screens i've had before. You can also doomscroll on smaller screens.
Sorry but this is maximum level conspiratorial thinking. Meta probably has some created some incentive for OEMs to make larger screens by way of people liking content consumption but the idea that they’d be paying for that is ridiculous lol.