We don’t know. We used to think it was critical because we thought life evolved in tide pools. Obviously no tide, no tide pools. That might be true, but now there’s good reason to believe that life started first in the deep depths of the ocean at magma vents. If that’s the case, maybe the moon isn’t essential.
The moon did shield us from many impacts however. All those massive craters were rocks that would have hit earth.
The moon did shield us from many impacts however. All those massive craters were rocks that would have hit earth.