You're proving the point.

1) iPhones for example are ip68 rated while those are just ipx8/9

2) Do you want to be limited to the universe of those search results? Do you want to buy a Sony Xperia?

You can't make batteries directly replaceable at the same quality and price. There are tradeoffs. Obviously waterproof non-embedded batteries exist. Just like you could make a removable battery the same slimness as embedded. With massive tradeoffs. It's capacity will be terrible. No one is surprised a removable battery can be waterproof but the point is there are tradeoffs.

I don't see those options in the search results either way

In any case we heard the same sort of rationalization for getting rid of the headphone jack, so color me extremely skeptical-- yes of course there's going to be trade-offs, but what a coincidence that headphone jacks, replaceable batteries, SD card slots have all gone by the wayside, which just so happens to allow for upselling Bluetooth and cloud storage

1 mm thickness is a fine trade-off

> just ipx8/9

Do you actually need it? For what?