Erosion makes gravel and sand, which are quite useful. It also makes minerals and nutrients accessible to life.

But we spend a lot of time and money managing erosion, and at the same time (often accidentally) create lots of erosion in other places. I doubt extracting tidal energy will have effects on a global scale, though it might cause some local changes

I think he's referring to nature making less florida.

OTOH there's a case to be made for keeping florida diluted.

erosion actually creates nests for various sea birds