If the iPhone 14 Pro is water resistance, how they mentioned that a warranty coverage doesn’t include water damage?

Official Apple site about water resistance:

About splash, water, and dust resistance of iPhone 7 and later - Apple Support

To prevent liquid damage, avoid these:

• Swimming or bathing with your iPhone
• Exposing your iPhone to pressurized water or high velocity water, such as when showering, water skiing, wake boarding, surfing, jet skiing, and so on
• Using your iPhone in a sauna or steam room
• Intentionally submerging your iPhone in water
• Operating your iPhone outside the suggested temperature ranges or in extremely humid conditions
• Dropping your iPhone or subjecting it to other impacts
• Disassembling your iPhone, including removing screws

Minimize exposing your iPhone to soap, detergent, acids or acidic foods, and any liquids—for example, perfume, insect repellent, lotions, sunscreen, oil, adhesive remover, hair dye, and solvents.

Yes, they tested the iPhone in lab controlled conditions, which aren't exactly real life, like dropping your phone overboard, taking it for a swim in the pool or ocean, dropping it in a toilet. Under strict lab conditions, the phone stood up to the conditions it was designed to meet. That doesn't mean you can drop your phone in water, pour coffee or a soft drink on it, accidentally drop it in a toilet (which unfortunately happens to some people). And if the phone is damaged by liquid intrusion, which Apple doesn't guarantee against, then the user will have to either purchase an "out of warranty" replacement or a new iPhone as it is simply not covered under Apple's standard warranty.

So you need to do your best to avoid getting your iPhone wet. For if you do and it is damaged, it's going to cost you. And that's that. There really is no point in discussing this further. We aren't Apple. We are all users on this user to user only forum. We didn't engineer iPhone. We don't provide its warranty. Feel free to share your thoughts with Apple here --> Feedback - iPhone - Apple

You take care and I do hope your iPhone is safe and not damaged my liquid, now or in the future.

Perhaps this will make it clear→Understanding Water Resistance - Apple Community

Because water resistant does not mean WATERPROOF. And resistance can become less with use. No iPhone ever built has includef warranty coverage for liquid damage.

You can present all the info that you want, but if the phone was damaged by water, Apple is not going to cover repairs or replacement.

Why ?

Non of the users here are Apple Employees.

What are you asking “Why ?” about? You asked the original poster, who asked a question. Are you asking Why the original poster asked the question? Probably because they wanted an answer.