system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does depth matter in regards to water resistance on cell phones? The new iPhone is rated for up to 6 meters for 30 minutes. Why is 6 meters ok when anything deeper isn’t? Does pressure matter that close to the surface?
gpt
You answered your question already: pressure.

Small slits and sealings fail at certain pressure. 
Pressure increases rapidly under water. Starting from the surface, pressure increases by 1 atm (100 kPa) every 10m.

1 atm at surface level

2 atm at -10m

3 atm at -20m

and so on.