Just ignoring the flimsy SAT metric, there's something most aren't considering in these sort of data. Cell phones enable and are fairly widely used for all sorts of cheating. Banning them gets rid of that, and so if there was no positive effect from a phone ban you'd actually probably expect a slight decrease on scores because of this effect.

So the fact that basically every school region that bans phones is seeing marginal to moderate gains is just huge. And as others have mentioned, test scores are but one aspect of this. Breaks where kids are playing and interacting more regularly are a million times better than ones where everybody whips out their screen and turns into a zombie.