what would happen to the earth if we completely destroyed the moon?

I'd think there would be a debris field that would orbit the Earth.
From space, Earth might look a bit like Saturn.

And since the Moon is responsible for the tides, the oceans would lose
ebb tide and flood tide.

Scriptor

The ocean tides would nearly disappear. Huge swaths of life that exist
in tidal areas would be eliminated. Page D-6 of the paper would have a
four inch by one column hole.

Going back a few years, if the Earth had no moon life would very
likely not have developed.

It depends on exactly what you mean by "destroy the Moon".

There would certainly be no werewolves.