I'm not denying that there are some trade-offs, but I'm also not strictly speaking about phones here. Think electric toothbrushes, trimmers, Bluetooth speakers and the other endless amounts of electric things with rechargeable batteries that don't have the space constraints of a phone.
It's weird to me that your line of thinking is actually a thing. It is not difficult to make a water-tight battery compartment for an electric toothbrush, but also make it trivial to open up and replace the battery. Hell, I just did a quick search for "electric toothbrush AAA battery", and these things exist and presumably work fine.
I feel like modern phones and the marketing around them (mostly from Apple) has pushed this nonsense that it's difficult to make water-resistant or water-proof electronics that still have a user-replaceable battery. Unfortunately this marketing seems to be working. Worked on you, at least. Gaskets, o-rings, and pressure seals are old, time-tested technology.
Admittedly it isn't as easy to make a water-resistant smartphone as it is to make water-resistant electric toothbrush. But it's far from impossible.
A toothbrush doesn't have the same space constraints, so they can just have relatively large seals, and they seal a relatively small opening (enough to fit a AA battery through).
It might well be possible to do this in a phone, but this sort of reasoning to come to that conclusion seems faulty. Like saying "Phones should be able to blow buildings apart. After all, tanks do it, so it's clearly possible."
It's not my area of expertise so I might just be delusional here, but from my understanding phones are difficult to make waterproof if they had replaceable batteries because they require a massive lid that spans across the entire phone while having a limited amount of thickness to work with and also because they have some expectations about the depth at which they remain waterproof. You don't necessarily have these constraints with a toothbrush. You can have a small opening at the bottom where you insert a tall battery and have plenty of height left to make a waterproof hatch. You're also unlikely to submerge your toothbrush in more than 50cm of water, like in the event of dropping it in the bathtub.
> Also, anecdotally, I’ve never had a sonicare toothbrush battery die. They still last weeks after many many years of use.
Sure, these exist too, though it doesn't reflect the majority of items which cheap out on all components, including batteries.
> Also, anecdotally, I’ve never had a sonicare toothbrush battery die. They still last weeks after many many years of use.
It’s the same for me, the whole toothbrush died two times shortly after warranty ended, with the battery having no issues. Not touching sonicare ever again. The cheap honeywell Chinese whatever brand is far more reliable for a small fraction of the price.
but you don't go diving with your bathroom devices. they need just splash protection which is not that complicated. i bet inventive competitor can come up with how to solve this problem efficiently and be rewarded by market.
