I don't believe that Earth is so special it's the only planet that can hold life. There are two TRILLION observable galaxies out there, some even 10 times bigger that the milky way, and the biggest known is 60 times bigger. And you want me to believe that we are the only life in the universe? Hell, i believe that there is life in milky way beside us.
Have they visited Earth? Hell no, everyone would know if they did. I mean, Proxima Centauri is 4 light years ahead, humans reached only 40,000 km per hour while light speed is 300,000 km per SECOND, so unless aliens found negative mass and developed war drive, the sheer size between stars wouldn't let them reach us, let alone size of galaxies.
Have they visited Earth? Hell no, everyone would know if they did. I mean, Proxima Centauri is 4 light years ahead, humans reached only 40,000 km per hour while light speed is 300,000 km per SECOND, so unless aliens found negative mass and developed war drive, the sheer size between stars wouldn't let them reach us, let alone size of galaxies.
Look how far we came from 500 years ago
If there is a civilization that is a million years ahead of us nothing would be impossible for them imo