Maybe "profit" is the wrong word. Anecdotally, the US has a lot of dedicated & spacious cell phone stores compared to other countries I've been in (where selling SIM cards is part of another store, like a 7-11 or an electronics store).

It's possible there's an extra $14/month in revenue going towards cell phones as an industry but due to the competition such as it is, it's mostly being spent on more aggressive GTM expenses.