iPhone 13 Pro is NOT water resistant...

The water resistance test as mentioned is done under controlled conditions including no water pressure when placing it in the temperature controlled pure still water. Yours fell in thus causing water pressure, I'm assuming the water was hot, and if you had been using soap on yourself, and possible oils, suds, etc. it was not pure. All of which are outside the water resistance specification. And you really shouldn't ever have electronics near water like that.

So you had pure water, you carefully placed your iPhone in the water, the water was at a neutral temperature? You said you dropped it in the water, that nullifies part of the test. All of those standards long precede the iPhone, they were ratings for wrist watches. No one in the watch world is going to take an IP68 or IP67 watch near water. If it isn't rated to 200 meters it isn't worth the chance. No, your experience did not make it a false statement. If you had dropped your Rolex with an IP68 rating into your bathtub you would be paying to repair it.

So you were in less than lukewarm water? Why? And you down use any kind of soap to clean?

But the sliding off the side of the bathtub adds water pressure that isn't present in testing. And Apple just said it passed standardized testing to achieve the IP68 certification. If you got water in the phone it then exceeded the IP68 rating. And do keep in mind the water resistance reduces over time.

It's not a manufacture's defect. Water resistant testing is done under very strict regulations. When you drop a device, it can warp the case and crack the seal thus letting water in.

An iPhone is splash resistant only. No iPhone is waterproof. Accidental damage is not covered by the warranty.

You're wrong