I own a $30 Casio watch, good to 100 meters that will last for about 10 years with reasonable battery replacement and a bit of good luck - My question would be why anybody would buy either a Swiss watch or an Apple Watch. meh. What a waste of money.
You are making the classic mistake of assuming your Casio and Swiss watches and the Apple Watch are the same product category. They are not. The first two merely keeps time. The Apple Watch is a wrist mounted computer that interfaces with your iPhone, facilitates payments, receives phone calls and messages, mail, and alerts, and can run other apps one of which also keeps time.
Your Casio tells times. The Swiss Watch tells time in various formats.