I think because we've seen cat 5s do less damage across the nation. The category is for wind strength and doesn't necessarily corelate with flooding /rain fall

It's a wet category 4. It's the type that carries months of rain and looks for a place to dump it all in a few hours. They create a lot of flood damage. A dry cat 4 would do wind damage and storm surges but not the water bombing.

The scale doesn't say how wet a storm is, just how fast the wind is. Revising this scale is still being discussed.

Last I read this morning it was still a category 4 and never made 5.