If it's true it would explain why ancient people wrote about it. It could explain why only humans have languages and make complex tools and dwellings and why we don't have fur and possibly even how humans managed to survive at all since a naked human is one of the most helpless creatures on the planet. I believe it's safe to say that few humans today could survive naked on the plains of Africa very long, for example. It would also explain how our moon got into such an unlikely orbit and rotation position and why it's the distance between Earth and sun to give the sort of eclipse it does. The list goes on, yet you can't appreciate any of those things, can you? I can though because for some reason I finally realised how it all could tie together and make sense of a bunch of things that don't seem to make sense on their own. In general I believe it's more likely than not that space traveling beings have project planets some places in the universe, so from that pov there's no reason to believe we aren't living on one. From that position, considering things it would explain if it were true makes it seem more likely than not that we really are on one.
I find it amazing that aliens could have moved our moon into position but when it came to building the pyramids they needed humans to haul the stones.
Your realization came not from an abundance of evidence but from the variety of fantasy stories that exist in the world and you so want those stories to be true you will ignore the lack of evidence to support them and any evidence that may contradict them.
The reason not to believe in project planets in the universe and the Earth being one of them is there is no evidence to support it.