Water is great but if it is unexpected, not so good. Ability to be notified when you sink or refrigerator is leaking is great.
The water heater is another almost silent leaker. When it goes, you do not want to see a river running down your driveway.
We use the Samsung Smartthings hub with several water sensors attached under sink, refrigerator, washer and water heater. Other than changing batteries rarely, they give me some sense of comfort.
The hub is useful for other sensors as well.