If I have to choose between easy-to-replace batteries and water resistance, I will go with the latter. Of course if both are possible, I would be very happy, but I just don’t see an engineering way for that in such a compact body as phones. Also, batteries are no longer 1-2 inches heigh, they are often odd-shaped to fill all the rest of the phone body.

Samsung still manages to do both removable batteries and water resistance in their Galaxy XCover line but I suppose thickness, weight, etc. are more important for the average consumer.

Samsung mocked Apple for removing the 3.5mm jack, but a few months later, did it themselves. Because the majority of consumers don’t care enough to do anything about it.