Cheap and easy enough to change. If you have to question it, probably a wise idea to change it?
At least if the belt goes, the water pump still works.
I replaced the belt on my car, only to find it is less than 6 months starting to have cracks on the grooves.
Turned out my one way alternator pulley was actually frozen and causing a lot of stress on the belt, changed pulley and put a new belt on, this was about 8k miles ago and so far no issue.
I find it is wise to replace serpentine belts by 7 years/70k miles. Probably best to do it as PM every 4 years/40k miles.
Why risk it breaking and causing other problems. If you change it on your schedule, you can control the cost and when it gets replaced. If you wait, it will always break when you least want it to and you cannot control the cost as well.