There aren't even that many of the original statues remaining. A lot of what survived are copies of the originals.

So, we are extrapolating from a very, very, very spotty data set.

No. 2000 years is a long time.

But you'd think at least some would be unearthed in Pompeii.

Most of Pompeii remains unexcavated, so there is still hope.

Latest excavation: https://www.pbs.org/video/episode-1-eyvf5d/ (Also on Apple TV)