Galaxy S5 was IP67-rated (1 metre depth, 30 minutes) and had a user-replaceable back cover / battery
Also a notification LED, OLED screen, bezels to pick the device up by, headphone jack, unlockable, a continuous light sensor... peak smartphone, save perhaps for the meager 200 Hz accelerometer refresh rate (modern phones have 500 Hz usually, I have no idea what for but I personally love toying with FFT plots)
If the headphone port flap was perfectly sealed….
*charge port flap
Waterproof phones all still have charging ports and no flaps. Not sure how but that seems to be solved. Maybe that one part's connectors are encased in glue?