Personally, I believe that they're worried about a repeat of this incident[0] - and the way they're ensuring that that can't happen is to test and 'certify' all

Personally, I believe that they're worried about a repeat of this incident[0] - and the way they're ensuring that that can't happen is to test and 'certify' all phones before customers are allowed to use them. Conveniently, they get to charge manufacturers for this certification process; and if consumers don't have a compatible phone, they get to advertise new expensive ones which come with installment plans. Overall, it's a win-win for AT&T, and a loss for customers. [0] https://www.theverge.com/2018/6/28/17515464/att-911-emergency-outage-fine-fcc-2017 https://www.theverge.com/2018/6/28/17515464/att-911-emergenc...