It's indeed frustrating to have a device, especially one as premium as the iPhone 13 Pro, get damaged from brief exposure to water. Your experience highlights a common misconception many consumers have.
Waterproof and water-resistant are terms that are often used interchangeably but have distinct meanings. When a device is labeled "water-resistant," it means that it can repel water to some extent but not entirely. Waterproof, on the other hand, suggests a higher level of protection, implying that the device can be submerged in water without any detrimental effects.
However, even with devices labeled as "waterproof," there are usually limits to the depth and duration of submersion they can handle. And with time, wear and tear, even minor ones, can compromise these protective features.
Manufacturers, including Apple, often have disclaimers about water and liquid damage. It's a reminder that while advancements in technology have made devices more durable, they aren't invincible. Additionally, seals and gaskets that provide this water resistance can degrade over time, reducing the effectiveness of the protection.
Your story serves as a cautionary tale for others: Always be cautious with electronics around water, regardless of their purported water resistance or proofing. While these features can offer some peace of mind, they shouldn't be overly relied upon.