If you are willing to trade heat and pry tools for thinness, that's a legitimate opinion, but please don't blame the trade-off on waterproofing.
The S7 (S6 for some reason didn’t get an IP rating?) got an IP68, 1.5m for 30 mins.
Samsung seems to have stalled at 1.5m/30mins.
iPhones on the other hand have steadily crept up their listed ratings for water resistance: 8: IP67 1m/30m 11: IP68 2m/30m 12: 68 6m/30m
Seems that you’re actually getting some advantage. 1 meter isn’t really good enough for dropping in, say, a pool or a lake. 6 meters on the other hand… should cover most scenarios.
Seems like a vanishingly small fraction of users are getting some advantage. Everyone else just pays.
A vanishingly small fraction of users take advantage of replacing their battery and instead just pass it along either in trade in, or in passing down to a family member/friend. This wasn’t any different when batteries were easily user replaceable.
You’re optimizing for an event that happens every few years instead of optimizing for something that is felt every single day (form factor, ergonomics, etc).
I've swam with my phone exactly zero times. Haven't dropped it in any deep water. But I have a bunch of devices with batteries barely holding any charge. And I suspect it's the most common situation.