I think the operative word here is 'let'.

The actual levers of control available to those in charge in schools are limited, in the end.

The rules that exist are routinely broken and can only be enforced selectively. Many of the rules are unpolicable frankly and are only kept to or only marginally broken as a matter of social norms, and understanding so there is not total choas. An equilbrium is found.

With phones there's such social pressure to allow their use, including from forces external to the school, that there was never possibly a hope of the equilibrium immediately settling at phones being banned.

It was always going to creep to the current status quo. Again this would have been true even if a rule were ostensibly set.

Society is learning, slowly, that this isn't ideal, and the pendulum seems to be swinging back. It may settle at phones being completely banned in schools, but in practice this will also obviously be moderately chipped away at all the time in various surprising and unsurprising ways. Especially as the hardware itself evolves.

> With phones there's such social pressure to allow their use, including from forces external to the school, that there was never possibly a hope of the equilibrium immediately settling at phones being banned.

Phones, and electronic devices in general, were always banned. What changed was schools started allowing them.

I was in high school right when some kids first started getting (dumb) cell phones. MP3 players were still new, CD players were not uncommon, and ALL of them were banned from being outside of your locker or backpack. If a teacher saw one, it was gone until the end of the day. Period.

Teachers didn't need to bear the brunt of angry parents, it wasn't their call to make. That belonged to the school administrator, who merely needed to say "tough shit". Somehow, the adult children still won anyway.