Bird Bath Traffic Disappointing

We maintain two bird baths here in the land of Cary BirdCam, and both are kept clean and filled. In addition the baths follow established guidelines: out of the sun, close enough to cover but not too close to provide a hiding place for predators. They're both shallow and roughly textured. In short, they should be fine places for birds to drink, bathe, or cool off. But for the last few years traffic has been so-so, regardless of season. BirdCam photography proves the point. I took two pictures in two days(!)--pretty hot days at that. Nor do I see exceptional photo counts at any time that BirdCam is watching. Explanations abound: better watering place elsewhere, possible safety issues of which I am not aware, too much shade...who can tell? Over time I do see good species representation but only the numbers escape me. Perhaps it is time to relocate the water feature and see what comes. Much to puzzle over...