Cats are descended from desert-dwelling ancestors, so they are not naturally inclined to get wet.
Cats have thick fur that helps to keep them warm, but it also makes them more susceptible to waterlogging.
Cats have very sensitive hearing, and the sound of running water can be very startling to them.
Cats also have very good vision, and the sight of water can be overwhelming to them.
If a cat has had a bad experience with water in the past, such as getting caught in the rain or being sprayed with a hose.
Some cats are simply more predisposed to being afraid of water than others. This may be due to their genetics or their individual personality.
It is possible to train a cat to be less afraid of water, but it takes time and patience. Start by introducing your cat to water slowly and gradually.