The iPhone X may have IP67 water resistance, but it is not recommended to use it while swimming or even showering.

This seems to be a safe way for Apple to avoid taking any responsibility, as everything shows that the iPhone X seems to be perfectly capable of surviving being submerged in water, even at great depths (unless the following is some kind of advertising gimmick from the company).
An iPhone X was recovered after two weeks from the bottom of a river, and after drying for three days, it was then returned to the owner, with everything working perfectly.
YouTuber Dallas, who owns the channel Man + River, while searching for lost items in a river discovered several valuable things, including a 10K ring and a silver iPhone X. As for the latter, Dallas decided to open it and let it dry, trying to get it working three days later.
If this is indeed a publicity stunt from Apple, it's incredibly well-crafted and could easily serve as an advertisement for the iPhone X.
The owner was Alyssa, who said she lost her iPhone X in the river about two weeks ago, adding that all the photos of her newborn baby were stored on the device. But magically, all the photos were recovered thanks to the iPhone X surviving these extreme conditions, even though it was not in a waterproof case.
The iPhone X wouldn't be able to survive being submerged in water for more than 30 minutes at a depth of one meter, according to official specifications. But as you can see in the video below, the device can actually withstand much harsher conditions, even without additional protection.
