

Let's look at the cave paintings with the knowledge we have by now
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I rewatched the cave paintings from the beginning of the show and I think I finally understand more of what they mean. They tell the story of the first people who arrived there and they actually got tricked into the same trap as everyone else.
Let's look at the colours used. Everything painted in red is connected to the red entity. Black symbolizes death and is also part of the entity.
White symbolizes everything ordinary, pure, full of life.
So the lighthouse is not a symbol of hope, it’s how the entity watches and reaches into the real world. The fallen tree was part of the trap from the beginning and a tool of the red entity.
After being trapped in the dark with no hope the people made the decision to make a sacrifice to this unknown entity/god out of fear.
But the ritual with the children only made things worse because it was a test. The land died, the harvest failed, shown with black colour, and the people slowly became part of the red entity itself.
Jade and Tabitha were the only ones who passed the test and escaped Fromville, because they simply refused to partake in the ritual. But they keep being reborn and returning as long as Fromville still exists.
Destroying the lighthouse might be the only way to finally end the cycle since it's the red entities tool and eyes.
By the way, I know a lot of people don't think this but in my opinion MiY is this entity or godlike creature. It makes sense also because the monsters are like little copies or "parts" of him just by far not as strong.