Nokia XR21 has IP69k and headphones jack. Galaxy Xcover6 pro has removable battery, headphone jack, and micro SD slot with IP68. S10e has IP68, headphone jack and SD card slot.
I don’t buy that headphone jack and SD card slot must disappear to achieve water resistance. They removed them because it was cheaper to produce and make you buy more expensive phone with bigger storage and wireless headphones once the battery degrades.
The limitation is not tech, it’s the cost to include those features in an IP68+ device. The XR21 is a $650USD phone, that’s near flagship prices, and very far from a budget phone.
Is it possible to create a device that has a jack, SD slot, and removable battery that’s also IP68+ certified? Absolutely, but doing that is quite a bit more expensive than the same features on an IP67 or lower device.
It’s not that it’s impossible, but the device will be both more expensive, and considerably thicker. Most people do not care about a headphone jack anymore, and even less so SD card slots and removable batteries. They want thinner, cheaper, waterproof phones. These features aren’t in high demand, and aren’t profitable for companies to produce.