Why you think it's not waterproof?
It's advertised as waterproof cell phone.
Many reviews say it's waterproof... But warranty not cover damage with water.
I think iPhone 7s will be better under water. Same as iPhone SE is better than iPhone 5s and they are same.
Complete waterproof cell phone is good feature but people could manipulate with that and if something else is broken they could say
"Water damage my phone, I want new one with more space and different color, because it's advertised as waterproof.
I never plan to jump in swimming pole with cell phone.
It's stupid but on heavy rain is 100% waterproof. I believe in that.
With Samsung S7 is similar, not work speakerphone, not work camera, touch screen and adevertised as waterpoof. I mean they cost a lot and it would be nice if they are really waterproof up to 5m, for sure. Apple have technology to do that because their phones are finer build than others.