Japan only, but KDDI/Kyocera never stopped IP rated phones with removable battery. TORQUE G07(2026) is IP65/68/69 rated with a coin key locked removable back cover.
It also officially support submersion in seawater as well as cleaning with soapy water. Most glued phones support neither.
It's just a consumer phone sold through KDDI retail channels. Not a B2B thing. And it exists because enough consumers in Japan buy one.
The original claims in this tree is that waterproof phones with removable backs are somehow impossible and glued shut designs are somehow superior. That's a total BS, so I posted a counter example. Torque phones being rugged in addition to being waterproof, unlike iPhones that are just purified-water-proof, has nothing to do with feasibility of one-upping them with removable backs and rubber gaskets.
It also officially support submersion in seawater as well as cleaning with soapy water. Most glued phones support neither.
1: https://k-tai.watch.impress.co.jp/docs/news/2088291.html