The moon slows the speed of rotation of the earth. The earth used to spin at 18hrs, rather then 24.
The moon acts as a climate regulator. If it weren’t there, the earth would not keep an even keel, causing major climate changes. The polar caps would change constantly.
Without the impact that caused the moon to emerge, the earth would be under water (mostly) and their would likely be a completely different atmosphere.
Primitive reproduction cycles would be different.
When we pulled our pants down in front of ppl and showed them our rear end, it wouldn't be called mooning ppl. I wonder what we would call it…..