I'm meticulous about maintaining battery health by using a Chargie device to limit charges to 80%, and a peltier cooled phone holder in the car that keeps it from overheating. Coupled with just not using the phone that much I'm pretty sure I can get 5-10 years of usable life out of the battery, and will probably replace the phone before that anyways.
My point is that the rating can be gamed, and relying on users to do something right is going to turn out badly for the users while the company points at small print.
[1] https://phandroid.com/2014/04/19/galaxy-s5-water-damage/amp/
And the iPhone 14 has had many years of improvements since the S5.
But outside my own forgetfulness, many people work outside in climates where heavy rain or snow is common.
Given that we normally carry these devices with us 24/7, it makes sense to build them to survive real-world 24/7 conditions.
1) Require fewer parts, so less expensive to make and more environment friendly
2) Last longer, so replacements come less often, thus more environment friendly
3) Higher recyclable battery rate, since Apple has incentive to recycle the used batteries, consumers less so.
The only benefit battery replaceable phone has is consumers having more control over their purchase and less likely to be screwed over by phone makers or sellers.
User replacable batteries are also user accessible controls to definitely power off the device. Usually devices without a replacable battery often have a secret handshake to power off, but it doesn't always work.
Back in the day they had special ruggedized phones for that use case (they still do) but it's nice just having a regular mass market phone with a good camera and not have to worry about it getting wet.
Also swimming pools, rivers, rain, snow… you can go lots of places where a phone would most likely or definitely get soaked or submerged, and it’s useful to have a phone with you for payment, maps, messages, everything you normally use it for. Water is the only thing that has killed/broken phones for me in years.