No reason other than the obvious. We like to hike streambed trails where/when available.Curious about your reasons for wanting waterproof. Other than the obvious.
I have waterproof mid/low hikers and they are fine in cool weather where I won't step too deep into water. But in warmer weather they get too hot and if I get in deep water, I get water seeping in around the top and then they take a long time to dry out. I used to wear them during my Boundary Water trips, but figured out that in that scenario water shoes or sandals are the best.
For day hikers, I wear a lightweight pair of boots with drain holes in them. I slop through whatever, the water drains out quickly and when I'm done for the day, they dry fairly fast.
I'd rather have mildly sweaty feet vs. wet feet & socks.
If I were doing way more than <10 miles a day day hiking (and RARELY ever consecutive days at that distance), I'd seriously consider non-waterproof boots.
I just hate socks wet from water intrusion.