Road bikes too. I wrecked my iPhone 8’s autofocus after riding ~1000 miles with it on a handlebar mount. Obviously there’s no engine vibration but chip-and-seal roads have a similar effect.
I've read the same, but my Pixel 3 had no issues after ~12.000km, half on it on asphalt, the other half on gravel and some rougher parts. Then a Motorola and a Xiaomi which I guess shared each half of the ~12.000km (two phones mounted, Xiaomi replaced Motorola halfway, both in parallel to the Pixel 3), where both of these devices (not the Pixel) were making automatic photos at geofenced spots during the ride (one of the street, to record the wet/dry condition, one of the selfie camera to record the sky condition cloud/sunny).
Though I do use a rubbery holder with good damping properties [1] and only recently moved over to a fixed one out of aluminum [2] for one of the phones, which could start causing this issue.
6S Plus did have OIS (in any case all cameras have autofocus which involves moving lens elements).
Probably the vibration in that situation didn't match the resonant modes of the camera components. It's probably a fairly rare event where everything lines up just right.
Though I do use a rubbery holder with good damping properties [1] and only recently moved over to a fixed one out of aluminum [2] for one of the phones, which could start causing this issue.
[1] https://www.amazon.de/gp/product/B06Y6C3P43
[2] https://www.amazon.de/gp/product/B07TQDMX6Z